Compare commits

...
Sign in to create a new pull request.

16 commits

Author SHA1 Message Date
Petr Menšík
660c264560 DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field (CVE-2026-13321)
[9.18] [CVE-2026-13321] sec: usr: Fix DNSSEC validation bypass via out-of-zone NSEC Next Field

A malicious zone with out-of-zone NSEC next owner names can cause a DNSSEC validating resolver to cache such record and, if `synth-from-dnssec` is enabled, to generate negative answers for any zone that is covered by the range.

ISC would like to thank Qifan Zhang of Palo Alto Networks for reporting the issue.

Closes isc-projects/bind9#5873
2026-08-26 11:07:49 +02:00
Petr Menšík
709fa352e1 Unexpected exit with NSEC and NSEC3 both present (CVE-2026-13204)
[9.18] [CVE-2026-13204] fix: usr: Prevent crash from malformed NSEC/NSEC3 response

An assertion could be triggered by an improperly signed NOQNAME proof. This has been fixed.

ISC thanks Qifan Zhang of Palo Alto Networks for reporting the issue.

Closes https://gitlab.isc.org/isc-projects/bind9/-/issues/5985
2026-08-26 11:07:49 +02:00
Petr Menšík
58ff7ce675 Incorrect acceptance of NSEC3 records (CVE-2026-10723)
[9.18] [CVE-2026-10723] sec: usr: Correct verification of NSEC3 signer name

BIND 9 accepted child-zone NSEC3 records where the first label equals the hash of the parent zone as valid parent-zone closest encloser proofs. This has been fixed.

ISC thanks Qifan Zhang of Palo Alto Networks for reporting the issue.

Closes isc-projects/bind9#5874
2026-08-26 11:07:49 +02:00
Petr Menšík
e1ee923bdc Cache poisoning via label count discrepancy, RRSIG, wildcards (CVE-2026-11721)
[9.18] [CVE-2026-11721] sec: usr: Invalid signed wildcard records were being accepted

Signed wildcard responses in which the Labels field in the `RRSIG` record was less than the number of labels in the Signer Name field were being incorrectly accepted. This in turn broke `synth-from-dnssec`, which depends on such records being correctly validated. This has been fixed.

ISC thanks Qifan Zhang of Palo Alto Networks for bringing this issue to our attention.

Closes https://gitlab.isc.org/isc-projects/bind9/-/issues/5871
2026-08-26 11:07:49 +02:00
Petr Menšík
13bacbc0e5 Potential memory usage beyond configured limits (CVE-2026-11622)
[9.18] [CVE-2026-11622] sec: usr: Prevent cache exhaustion under sustained attack

The cache memory can become exhausted with expired entries whose memory
is not released due to a sustained attack on the same DNS name that
prevents the cleanup.  This has been fixed.

Closes: https://gitlab.isc.org/isc-projects/bind9/-/work_items/4760
2026-08-26 11:07:49 +02:00
Petr Menšík
11e56f333e Record ordering based unexpected exit with CNAME or DNAME (CVE-2026-12617)
[9.18] [CVE-2026-12617] sec: usr: Do no assert for some specifics CNAME and DNAME queries

A bug in the resolver's handling of certain cached DNAME and CNAME responses could cause named to trigger an assertion failure and exit. An attacker controlling a domain name and the authoritative DNS server it is hosted on could exploit this behavior to cause a denial-of-service. This vulnerability has been fixed.

ISC thanks Qifan Zhang of Palo Alto Networks for bringing this issue to our attention.

Closes: isc-projects/bind9#5946

[9.18] fix: test: Stabilize the cname_dname_negcache test

The test proved unstable due to timing-related race condition, which could produce both false positive and false negative results. Use a more reliable mechanism to reproduce the issue.

Human-effort-level: low
2026-08-26 11:07:49 +02:00
Petr Menšík
bbad8f050e Key Record using PRIVATEDNS algorithm may lead to exit (CVE-2026-10822)
[9.18] [CVE-2026-10822] sec: usr: Fix dns_name_fromwire to record boundaries

Previously, `dns_name_fromwire()` did not honor the record boundary when reading names from the wire, allowing malformed records to be accepted when they should not have been. This has been fixed.

Closes: https://gitlab.isc.org/isc-projects/bind9/-/issues/6004
2026-08-26 11:07:49 +02:00
Petr Menšík
45353df914 Potential wildcard CNAME RPZ policy bypass (CVE-2026-11331)
[9.18] [CVE-2026-11331] sec: usr: Fix handling of rpz CNAME expansion that returns name too long

Previously, if the expansion of a wildcard CNAME RPZ policy resulted in a name that exceeded the length limit, a self referential CNAME and the original address record were returned, allowing the policy to be bypassed.  In branches up to 9.20, this also left query processing in an inconsistent state which could trigger an assertion failure.  We now return a YXDOMAIN response, without the address.

ISC would like to thank Laith Mash'al (0xmshal) for bringing this issue to our attention.

Closes https://gitlab.isc.org/isc-projects/bind9/-/issues/5856
2026-08-26 11:07:49 +02:00
Petr Menšík
95f9c884e4 Remove /etc/rwtab from the package 2026-06-24 17:45:00 +02:00
Petr Menšík
dad54b67dc Update to 9.18.50 (rhbz#2489833)
Removed Features:

- Remove ineffective TCP fallback after repeated UDP timeouts.

Feature Changes:

- Fall back to TCP on receipt of a UDP response with a mismatched query ID.

Bug Fixes:

- Fix DNS64 owner case after DNAME restart.
- Clear REDIRECT flag when it isn't needed.

This should be final release of BIND 9.18 line. That version is now
marked EOL.

Source: https://downloads.isc.org/isc/bind9/9.18.50/doc/arm/html/notes.html#notes-for-bind-9-18-50
2026-06-24 17:45:00 +02:00
Petr Menšík
8304916cfb Update to 9.18.49 (rhbz#2480121)
Security Fixes:

- Limit resolver server list size. (CVE-2026-3592)
- Fix GSS-API resource leak. (CVE-2026-3039)
- Disable recursion, UPDATE, and NOTIFY for non-IN views. (CVE-2026-5946)
- Avoid unbounded recursion loop. (CVE-2026-5950)
- Fix outgoing zone transfers' quota issue.

Feature Changes:

- Fix CPU spikes and slow queries when cache approaches memory limit.

Bug Fixes:

- Fix named crash when processing SIG records in dynamic updates.
- Fix rndc modzone behavior for a zone in named.conf.
- Fix zone verification of NSEC3 signed zones.
- Prevent a crash when using both dns64 and filter-aaaa.
- Fixed an assertion failure when processing catalog zones.
- Prevent malicious DNSSEC zones from exhausting validator CPU.
- Fix rndc-confgen aborting on HMAC-SHA-384/512 keys above 512 bits.
- Prevent crafted queries from degrading RRL performance.
- Fix a bug in allow-query/allow-transfer catalog zone custom properties.
- Fix a memory leak issue in catalog zones.
- Fix suppressed missing-glue check in named-checkzone.
- Reject record sets too large to serve in DNS.

Source: https://downloads.isc.org/isc/bind9/9.18.49/doc/arm/html/notes.html#notes-for-bind-9-18-49
2026-05-21 18:47:53 +02:00
Petr Menšík
4abe21fa8d Update to 9.18.48 (rhbz#2453853)
Security Fixes:

- Fix crash when reconfiguring zone update policy during active updates.

Bug Fixes:

- Fix a crash triggered by rndc modzone on a zone from a configuration file.
- Fix a crash triggered by rndc modzone on zone that already existed in NZF file.

Source: https://downloads.isc.org/isc/bind9/9.18.48/doc/arm/html/notes.html#notes-for-bind-9-18-48
2026-04-08 10:40:30 +02:00
Petr Menšík
674658d2e1 Update to 9.18.47 (rhbz#2440561)
Security Fixes:
- Fix unbounded NSEC3 iterations when validating referrals to unsigned delegations. (CVE-2026-1519)

Source: https://downloads.isc.org/isc/bind9/9.18.47/doc/arm/html/notes.html#notes-for-bind-9-18-47
2026-03-25 20:32:17 +01:00
Petr Menšík
1c68e87dbe Add forgotten _libdir/named into bind-chroot tmpfiles
One of libdir directories was forgotten. It is the directory containing
the actual plugin, might cause issues if filter-aaaa.so plugin is used.

Related: RHEL-132054
2026-03-25 20:32:17 +01:00
Petr Menšík
63420089a5 Create /var/named directories for bind-chroot
Fixes bind-chroot in Image Mode. Include even subdirectories.

Related: RHEL-132053
2026-03-25 20:32:17 +01:00
Petr Menšík
31b9cee7af Update to 9.18.44 (rhbz#2431609)
Security Fixes:

- Fix incorrect length checks for BRID and HHIT records. (CVE-2025-13878)

Bug Fixes:

- Allow glue in delegations with QTYPE=ANY.
- Reconfiguring an NSEC3 opt-out zone to NSEC caused the zone to be invalid.

https://downloads.isc.org/isc/bind9/9.18.44/doc/arm/html/notes.html#notes-for-bind-9-18-44
2026-01-22 19:38:24 +01:00
19 changed files with 4200 additions and 15 deletions

View file

@ -0,0 +1,854 @@
From 2a4786b0edde59274f682c9bd4ae4026c2d08218 Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Wed, 1 Jul 2026 22:56:02 -0700
Subject: [PATCH] add isctest.mark method for ecdsa_deterinistic
This checks support for ECDSA deterministic mode in the cryptography
library.
(cherry picked from commit 6e44151466864d3dd783a20da83d01028781d3e2)
(cherry picked from commit dc3f52388427f4f94087d984d5a2088b925810e2)
Reproducer for #5874 NSEC3 impersonation
LLM generated.
(cherry picked from commit f3e2eb333be3ac636f745aa13cfb8d9ee8af87d8)
(cherry picked from commit 35e3d49d2222c13786a06021c7ed583d2a656e51)
Update reproducer #5874
Update the llm generated reproducer:
- Move server.py into ans1/ans.py
- Remove unnecessary named.conf configuration options
- Add comments describing the steps (copied from GL issue)
- Rename system test
(cherry picked from commit c1321fef165a2ef8c2bff971901c58941e8e694c)
(cherry picked from commit 833dd3b230b92596074e8da15b12298f46c939f2)
---
bin/tests/system/chain/ans3/ans.py | 10 +-
bin/tests/system/chain/ans4/ans.py | 8 +-
bin/tests/system/cookie/ans9/ans.py | 7 +-
bin/tests/system/digdelv/ans8/ans.py | 7 +-
bin/tests/system/dnssec/ans10/ans.py | 11 +-
bin/tests/system/forward/ans11/ans.py | 12 +-
bin/tests/system/isctest/mark.py | 12 +
.../system/nsec3_impersonation/ans1/ans.py | 280 ++++++++++++++++++
.../nsec3_impersonation/ns2/named.conf.j2 | 33 +++
.../tests_nsec3_impersonation.py | 152 ++++++++++
bin/tests/system/qmin/ans2/ans.py | 11 +-
bin/tests/system/qmin/ans3/ans.py | 11 +-
bin/tests/system/qmin/ans4/ans.py | 11 +-
bin/tests/system/resolver/ans10/ans.py | 12 +-
14 files changed, 529 insertions(+), 48 deletions(-)
create mode 100644 bin/tests/system/nsec3_impersonation/ans1/ans.py
create mode 100644 bin/tests/system/nsec3_impersonation/ns2/named.conf.j2
create mode 100644 bin/tests/system/nsec3_impersonation/tests_nsec3_impersonation.py
diff --git a/bin/tests/system/chain/ans3/ans.py b/bin/tests/system/chain/ans3/ans.py
index 0a031c1145..7c54c3c51a 100644
--- a/bin/tests/system/chain/ans3/ans.py
+++ b/bin/tests/system/chain/ans3/ans.py
@@ -19,10 +19,10 @@ import sys
import signal
import socket
import select
-from datetime import datetime, timedelta
-import functools
-import dns, dns.message, dns.query
+import dns
+import dns.message
+import dns.query
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -173,9 +173,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/chain/ans4/ans.py b/bin/tests/system/chain/ans4/ans.py
index c969117368..de536b25bd 100755
--- a/bin/tests/system/chain/ans4/ans.py
+++ b/bin/tests/system/chain/ans4/ans.py
@@ -22,7 +22,9 @@ import select
from datetime import datetime, timedelta
import functools
-import dns, dns.message, dns.query
+import dns
+import dns.message
+import dns.query
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -371,9 +373,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/cookie/ans9/ans.py b/bin/tests/system/cookie/ans9/ans.py
index 3b0f82cc1d..2710386d74 100644
--- a/bin/tests/system/cookie/ans9/ans.py
+++ b/bin/tests/system/cookie/ans9/ans.py
@@ -15,9 +15,6 @@ import sys
import signal
import socket
import select
-from datetime import datetime, timedelta
-import time
-import functools
import dns
import dns.edns
@@ -257,9 +254,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/digdelv/ans8/ans.py b/bin/tests/system/digdelv/ans8/ans.py
index 3e18edc1cc..1896a2bafc 100644
--- a/bin/tests/system/digdelv/ans8/ans.py
+++ b/bin/tests/system/digdelv/ans8/ans.py
@@ -17,7 +17,8 @@ import socket
import select
import struct
-import dns, dns.message
+import dns
+import dns.message
from dns.rcode import *
modes = [
@@ -109,9 +110,9 @@ hung_conns = []
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/dnssec/ans10/ans.py b/bin/tests/system/dnssec/ans10/ans.py
index 84bf0a2642..46af72a147 100644
--- a/bin/tests/system/dnssec/ans10/ans.py
+++ b/bin/tests/system/dnssec/ans10/ans.py
@@ -16,10 +16,11 @@ import signal
import socket
import select
from datetime import datetime, timedelta
-import time
-import functools
-import dns, dns.message, dns.query, dns.flags
+import dns
+import dns.message
+import dns.query
+import dns.flags
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -140,9 +141,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/forward/ans11/ans.py b/bin/tests/system/forward/ans11/ans.py
index 00b5895f76..d5b8a5b037 100644
--- a/bin/tests/system/forward/ans11/ans.py
+++ b/bin/tests/system/forward/ans11/ans.py
@@ -16,11 +16,11 @@ import signal
import socket
import select
import struct
-from datetime import datetime, timedelta
-import time
-import functools
-import dns, dns.message, dns.query, dns.flags
+import dns
+import dns.message
+import dns.query
+import dns.flags
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -192,9 +192,9 @@ hung_conns = []
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/isctest/mark.py b/bin/tests/system/isctest/mark.py
index 53860a806c..098af5acfc 100644
--- a/bin/tests/system/isctest/mark.py
+++ b/bin/tests/system/isctest/mark.py
@@ -88,3 +88,15 @@ softhsm2_environment = pytest.mark.skipif(
),
reason="SOFTHSM2_CONF and SOFTHSM2_MODULE environmental variables must be set and pkcs11-tool and softhsm2-util tools present",
)
+
+ecdsa_deterministic = False
+try:
+ from cryptography.hazmat.backends import default_backend
+
+ ecdsa_deterministic = default_backend().ecdsa_deterministic_supported()
+except Exception: # pylint: disable=broad-except
+ pass
+
+with_ecdsa_deterministic = pytest.mark.skipif(
+ not ecdsa_deterministic, reason="ECDSA deterministic signing is not supported"
+)
diff --git a/bin/tests/system/nsec3_impersonation/ans1/ans.py b/bin/tests/system/nsec3_impersonation/ans1/ans.py
new file mode 100644
index 0000000000..177e79c195
--- /dev/null
+++ b/bin/tests/system/nsec3_impersonation/ans1/ans.py
@@ -0,0 +1,280 @@
+#!/usr/bin/python3
+
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+from collections.abc import AsyncGenerator
+from dataclasses import dataclass
+from pathlib import Path
+
+import json
+
+from cryptography.hazmat.primitives import serialization
+
+import dns.dnssec
+import dns.flags
+import dns.message
+import dns.name
+import dns.rcode
+import dns.rdata
+import dns.rdataclass
+import dns.rdatatype
+import dns.rrset
+
+from isctest.asyncserver import (
+ AsyncDnsServer,
+ DnsResponseSend,
+ QueryContext,
+ ResponseHandler,
+)
+
+TTL = 300
+TLD = "tld.test."
+APEX_HASH = "1B40241KFORIOG780N4IKSCRLVETPCTQ"
+ATTACKER = f"{APEX_HASH.lower()}.{TLD}"
+VICTIM = f"victim.{TLD}"
+AUTH_IP = "10.53.0.1"
+
+
+@dataclass(frozen=True)
+class Key:
+ zone: dns.name.Name
+ private_key: object
+ dnskey: dns.rdata.Rdata
+ ds: dns.rdata.Rdata
+
+
+def name(text: str) -> dns.name.Name:
+ return dns.name.from_text(text)
+
+
+def load_keys() -> dict[str, Key]:
+ path = Path(__file__).resolve().parent / "keys.json"
+ with path.open(encoding="utf-8") as keys_file:
+ raw_keys = json.load(keys_file)
+
+ keys = {}
+ for zone, raw_key in raw_keys.items():
+ private_key = serialization.load_pem_private_key(
+ raw_key["private_pem"].encode("ascii"),
+ password=None,
+ )
+ dnskey = dns.rdata.from_text(
+ dns.rdataclass.IN, dns.rdatatype.DNSKEY, raw_key["dnskey"]
+ )
+ ds = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.DS, raw_key["ds"])
+ keys[zone] = Key(name(zone), private_key, dnskey, ds)
+
+ return keys
+
+
+def rrset(owner: str, rdtype: dns.rdatatype.RdataType, *rdatas: str) -> dns.rrset.RRset:
+ return dns.rrset.from_text(owner, TTL, dns.rdataclass.IN, rdtype, *rdatas)
+
+
+def rrset_from_rdata(owner: str, rdata: dns.rdata.Rdata) -> dns.rrset.RRset:
+ return dns.rrset.from_rdata(name(owner), TTL, rdata)
+
+
+def rrsig_rrset(covered: dns.rrset.RRset, signer: Key) -> dns.rrset.RRset:
+ rrsig = dns.dnssec.sign(
+ covered,
+ signer.private_key,
+ signer.zone,
+ signer.dnskey,
+ lifetime=86400,
+ verify=True,
+ )
+ return dns.rrset.from_rdata(covered.name, covered.ttl, rrsig)
+
+
+def add_signed(
+ section: list[dns.rrset.RRset], covered: dns.rrset.RRset, signer: Key
+) -> None:
+ section.append(covered)
+ section.append(rrsig_rrset(covered, signer))
+
+
+def dnskey_rrset(zone: str, zone_key: Key) -> dns.rrset.RRset:
+ return rrset_from_rdata(zone, zone_key.dnskey)
+
+
+def ds_rrset(zone: str, zone_key: Key) -> dns.rrset.RRset:
+ return rrset_from_rdata(zone, zone_key.ds)
+
+
+def soa_rrset(zone: str) -> dns.rrset.RRset:
+ return rrset(
+ zone,
+ dns.rdatatype.SOA,
+ f"ns.{zone} hostmaster.{zone} 1 3600 600 86400 300",
+ )
+
+
+def ns_rrset(zone: str, ns_target: str) -> dns.rrset.RRset:
+ return rrset(zone, dns.rdatatype.NS, ns_target)
+
+
+def glue_rrset(ns_target: str, address: str) -> dns.rrset.RRset:
+ return rrset(ns_target, dns.rdatatype.A, address)
+
+
+def answer_dnskey(response: dns.message.Message, zone: str, zone_key: Key) -> None:
+ add_signed(response.answer, dnskey_rrset(zone, zone_key), zone_key)
+
+
+def answer_soa(response: dns.message.Message, zone: str, zone_key: Key) -> None:
+ add_signed(response.answer, soa_rrset(zone), zone_key)
+
+
+def answer_ns(
+ response: dns.message.Message, zone: str, ns_target: str, zone_key: Key
+) -> None:
+ add_signed(response.answer, ns_rrset(zone, ns_target), zone_key)
+
+
+class SignedResponseHandler(ResponseHandler):
+ def __init__(self, keys: dict[str, Key]) -> None:
+ self.keys = keys
+
+ async def get_responses(
+ self, qctx: QueryContext
+ ) -> AsyncGenerator[DnsResponseSend, None]:
+ qctx.prepare_new_response(with_zone_data=False)
+ qctx.response.flags |= dns.flags.AA
+ qctx.response.set_rcode(dns.rcode.NOERROR)
+ self.respond(qctx)
+ yield DnsResponseSend(qctx.response, authoritative=True)
+
+ def respond(self, qctx: QueryContext) -> None:
+ raise NotImplementedError
+
+
+def child_nsec3_rrset() -> dns.rrset.RRset:
+ rdata = dns.rdata.from_text(
+ dns.rdataclass.IN,
+ dns.rdatatype.NSEC3,
+ f"1 0 0 - {APEX_HASH} NS SOA RRSIG DNSKEY NSEC3PARAM",
+ )
+ return dns.rrset.from_rdata(name(f"{APEX_HASH}.{TLD}"), TTL, rdata)
+
+
+def forged_nxdomain(response: dns.message.Message, keys: dict[str, Key]) -> None:
+ response.set_rcode(dns.rcode.NXDOMAIN)
+
+ add_signed(response.authority, soa_rrset(TLD), keys[TLD])
+
+ # The owner name derives zone "tld.test.", but the RRSIG signer is the
+ # malicious child zone "1b40241kforiog780n4ikscrlvetpctq.tld.test.".
+ add_signed(response.authority, child_nsec3_rrset(), keys[ATTACKER])
+
+
+class VictimForgedNxdomainHandler(SignedResponseHandler):
+ """
+ This serves the forged response for the victim's domain.
+ """
+
+ def match(self, qctx: QueryContext) -> bool:
+ return qctx.qname == name(VICTIM) and qctx.qtype == dns.rdatatype.A
+
+ def respond(self, qctx: QueryContext) -> None:
+ forged_nxdomain(qctx.response, self.keys)
+
+
+class ChildDsHandler(SignedResponseHandler):
+ """
+ This will spoof the response for the malicious zone when qtype is DS.
+ It is actually a validly signed DS response.
+ """
+
+ def match(self, qctx: QueryContext) -> bool:
+ return qctx.qname == name(ATTACKER) and qctx.qtype == dns.rdatatype.DS
+
+ def respond(self, qctx: QueryContext) -> None:
+ response = qctx.response
+ zone = ATTACKER
+ child_key = self.keys[ATTACKER]
+ parent_key = self.keys[TLD]
+
+ add_signed(response.answer, ds_rrset(zone, child_key), parent_key)
+
+
+class AttackerZoneHandler(SignedResponseHandler):
+ """
+ Acts as the malicious authoritative name server. The zone being served
+ is the hashed label of the parent zone (tld.test). This will respond
+ for all queries qtype SOA, DNSKEY, NS at the apex. Any names below
+ the apex are answered with an NXDOMAIN with no NSEC or NSEC3 present.
+ """
+
+ def match(self, qctx: QueryContext) -> bool:
+ return qctx.qname.is_subdomain(name(ATTACKER))
+
+ def respond(self, qctx: QueryContext) -> None:
+ if qctx.qname == name(ATTACKER):
+ if qctx.qtype == dns.rdatatype.DNSKEY:
+ answer_dnskey(qctx.response, ATTACKER, self.keys[ATTACKER])
+ elif qctx.qtype == dns.rdatatype.SOA:
+ answer_soa(qctx.response, ATTACKER, self.keys[ATTACKER])
+ else:
+ answer_ns(
+ qctx.response, ATTACKER, f"ns.{ATTACKER}", self.keys[ATTACKER]
+ )
+ qctx.response.additional.append(glue_rrset(f"ns.{ATTACKER}", AUTH_IP))
+ return
+
+ qctx.response.set_rcode(dns.rcode.NXDOMAIN)
+ add_signed(qctx.response.authority, soa_rrset(ATTACKER), self.keys[ATTACKER])
+
+
+class TldZoneHandler(SignedResponseHandler):
+ """
+ Acts as the TLD who is being used in the attack, but is not a standard
+ name server. It only responds with validly signed records for DNSKEY, SOA
+ and NS on the apex. Any names below the apex are answered with an NXDOMAIN
+ with no NSEC or NSEC3 present.
+
+ If we turn this into a regular name server than the attack won't work.
+ The attack assumes that the adversary can inject these responses on-path.
+ """
+
+ def match(self, qctx: QueryContext) -> bool:
+ return qctx.qname.is_subdomain(name(TLD))
+
+ def respond(self, qctx: QueryContext) -> None:
+ if qctx.qname == name(TLD):
+ if qctx.qtype == dns.rdatatype.DNSKEY:
+ answer_dnskey(qctx.response, TLD, self.keys[TLD])
+ elif qctx.qtype == dns.rdatatype.SOA:
+ answer_soa(qctx.response, TLD, self.keys[TLD])
+ else:
+ answer_ns(qctx.response, TLD, "ns.tld.test.", self.keys[TLD])
+ qctx.response.additional.append(glue_rrset("ns.tld.test.", AUTH_IP))
+ return
+
+ qctx.response.set_rcode(dns.rcode.NXDOMAIN)
+ add_signed(qctx.response.authority, soa_rrset(TLD), self.keys[TLD])
+
+
+def main() -> None:
+ keys = load_keys()
+ server = AsyncDnsServer(default_aa=True)
+ server.install_response_handlers(
+ VictimForgedNxdomainHandler(keys),
+ ChildDsHandler(keys),
+ AttackerZoneHandler(keys),
+ TldZoneHandler(keys),
+ )
+ server.run()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/bin/tests/system/nsec3_impersonation/ns2/named.conf.j2 b/bin/tests/system/nsec3_impersonation/ns2/named.conf.j2
new file mode 100644
index 0000000000..2c9b0bba9e
--- /dev/null
+++ b/bin/tests/system/nsec3_impersonation/ns2/named.conf.j2
@@ -0,0 +1,33 @@
+// validating resolver
+
+options {
+ query-source address 10.53.0.2;
+ notify-source 10.53.0.2;
+ transfer-source 10.53.0.2;
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { 10.53.0.2; };
+ listen-on-v6 { none; };
+ recursion yes;
+ dnssec-validation yes;
+};
+
+controls {
+ inet 10.53.0.2 port @CONTROLPORT@ allow { any; } keys { rndc_key; };
+};
+
+include "../../_common/rndc.key";
+
+zone "." {
+ type hint;
+ file "../../_common/root.hint";
+};
+
+zone "tld.test" {
+ type static-stub;
+ server-addresses { 10.53.0.1; };
+};
+
+trust-anchors {
+ tld.test. static-key 257 3 13 "@TLD_DNSKEY@";
+};
diff --git a/bin/tests/system/nsec3_impersonation/tests_nsec3_impersonation.py b/bin/tests/system/nsec3_impersonation/tests_nsec3_impersonation.py
new file mode 100644
index 0000000000..bd9bd275b6
--- /dev/null
+++ b/bin/tests/system/nsec3_impersonation/tests_nsec3_impersonation.py
@@ -0,0 +1,152 @@
+#!/usr/bin/python3
+
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+from pathlib import Path
+
+import json
+
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import ec
+
+import dns.dnssec
+import dns.flags
+import dns.name
+import dns.rdataclass
+import dns.rdatatype
+import pytest
+
+import isctest
+import isctest.mark
+
+APEX_HASH = "1B40241KFORIOG780N4IKSCRLVETPCTQ"
+ATTACKER = f"{APEX_HASH.lower()}.tld.test."
+VICTIM = "victim.tld.test."
+AUTH = "10.53.0.1"
+RESOLVER = "10.53.0.2"
+
+pytestmark = [
+ isctest.mark.with_ecdsa_deterministic,
+ pytest.mark.extra_artifacts(
+ [
+ "ans*/ans.run",
+ "ans*/keys.json",
+ ]
+ ),
+]
+
+
+def _make_key(zone):
+ private_key = ec.generate_private_key(ec.SECP256R1())
+ dnskey = dns.dnssec.make_dnskey(
+ private_key.public_key(),
+ algorithm="ECDSAP256SHA256",
+ flags=257,
+ )
+ ds = dns.dnssec.make_ds(dns.name.from_text(zone), dnskey, "SHA256")
+ private_pem = private_key.private_bytes(
+ encoding=serialization.Encoding.PEM,
+ format=serialization.PrivateFormat.PKCS8,
+ encryption_algorithm=serialization.NoEncryption(),
+ ).decode("ascii")
+ return {
+ "private_pem": private_pem,
+ "dnskey": dnskey.to_text(),
+ "ds": ds.to_text(),
+ }
+
+
+def bootstrap():
+ zones = ["tld.test.", ATTACKER]
+ keys = {zone: _make_key(zone) for zone in zones}
+
+ Path("ans1/keys.json").write_text(json.dumps(keys, indent=2), encoding="ascii")
+
+ tld_dnskey = "".join(keys["tld.test."]["dnskey"].split()[3:])
+ return {"TLD_DNSKEY": tld_dnskey}
+
+
+def check_dnskey_response(zone):
+ query = isctest.query.create(zone, "DNSKEY")
+ response = isctest.query.tcp(query, AUTH)
+
+ isctest.check.noerror(response)
+ assert response.flags & dns.flags.AA
+ assert (
+ response.get_rrset(
+ response.answer,
+ dns.name.from_text(zone),
+ dns.rdataclass.IN,
+ dns.rdatatype.DNSKEY,
+ )
+ is not None
+ ), response
+
+
+def check_ds_response(zone):
+ query = isctest.query.create(zone, "DS")
+ response = isctest.query.tcp(query, AUTH)
+
+ isctest.check.noerror(response)
+ assert response.flags & dns.flags.AA
+ assert (
+ response.get_rrset(
+ response.answer,
+ dns.name.from_text(zone),
+ dns.rdataclass.IN,
+ dns.rdatatype.DS,
+ )
+ is not None
+ ), response
+
+
+def test_attack_responses():
+ check_dnskey_response("tld.test.")
+ check_dnskey_response(ATTACKER)
+ check_ds_response(ATTACKER)
+
+ query = isctest.query.create(VICTIM, "A")
+ response = isctest.query.tcp(query, AUTH)
+
+ isctest.check.nxdomain(response)
+ assert response.flags & dns.flags.AA
+
+ nsec3_owner = dns.name.from_text(f"{APEX_HASH}.tld.test.")
+ nsec3 = response.get_rrset(
+ response.authority,
+ nsec3_owner,
+ dns.rdataclass.IN,
+ dns.rdatatype.NSEC3,
+ )
+ rrsig = response.get_rrset(
+ response.authority,
+ nsec3_owner,
+ dns.rdataclass.IN,
+ dns.rdatatype.RRSIG,
+ covers=dns.rdatatype.NSEC3,
+ )
+
+ assert nsec3 is not None, response
+ assert rrsig is not None, response
+ assert rrsig[0].signer == dns.name.from_text(ATTACKER)
+
+
+def test_nsec3_impersonation():
+ """
+ Reproducer for #5874:
+ F-006 DNSSEC Validation Bypass NSEC3 Apex Hash Label Parent Impersonation
+ """
+ query = isctest.query.create(VICTIM, "A")
+ response = isctest.query.tcp(query, RESOLVER)
+
+ isctest.check.noadflag(response)
+ isctest.check.servfail(response)
diff --git a/bin/tests/system/qmin/ans2/ans.py b/bin/tests/system/qmin/ans2/ans.py
index d372c2003b..9343fbc8ef 100755
--- a/bin/tests/system/qmin/ans2/ans.py
+++ b/bin/tests/system/qmin/ans2/ans.py
@@ -15,11 +15,12 @@ import sys
import signal
import socket
import select
-from datetime import datetime, timedelta
import time
-import functools
-import dns, dns.message, dns.query, dns.flags
+import dns
+import dns.message
+import dns.query
+import dns.flags
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -432,9 +433,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/qmin/ans3/ans.py b/bin/tests/system/qmin/ans3/ans.py
index b5ae73c3fa..4e7250790f 100755
--- a/bin/tests/system/qmin/ans3/ans.py
+++ b/bin/tests/system/qmin/ans3/ans.py
@@ -15,11 +15,12 @@ import sys
import signal
import socket
import select
-from datetime import datetime, timedelta
import time
-import functools
-import dns, dns.message, dns.query, dns.flags
+import dns
+import dns.message
+import dns.query
+import dns.flags
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -261,9 +262,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/qmin/ans4/ans.py b/bin/tests/system/qmin/ans4/ans.py
index 517217aec1..2d5556daff 100755
--- a/bin/tests/system/qmin/ans4/ans.py
+++ b/bin/tests/system/qmin/ans4/ans.py
@@ -15,11 +15,12 @@ import sys
import signal
import socket
import select
-from datetime import datetime, timedelta
import time
-import functools
-import dns, dns.message, dns.query, dns.flags
+import dns
+import dns.message
+import dns.query
+import dns.flags
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -320,9 +321,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
diff --git a/bin/tests/system/resolver/ans10/ans.py b/bin/tests/system/resolver/ans10/ans.py
index 6e95dbbfc6..d637c63e5a 100644
--- a/bin/tests/system/resolver/ans10/ans.py
+++ b/bin/tests/system/resolver/ans10/ans.py
@@ -15,11 +15,11 @@ import sys
import signal
import socket
import select
-from datetime import datetime, timedelta
-import time
-import functools
-import dns, dns.message, dns.query, dns.flags
+import dns
+import dns.message
+import dns.query
+import dns.flags
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
@@ -128,9 +128,9 @@ else:
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
- except select.error as e:
+ except select.error:
break
- except socket.error as e:
+ except socket.error:
break
except KeyboardInterrupt:
break
--
2.55.0

View file

@ -0,0 +1,67 @@
From 608026780a43abe5b23a9af3af21808369032158 Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Thu, 21 May 2026 14:41:55 -0700
Subject: [PATCH] Check NSEC3 signer matches the owning zone
When validating NSEC3 records, reject any signature whose signer field
does not match the zone owning the NSEC3.
This ensures that a child zone cannot impersonate its parent and forge
NXDOMAIN responses for sibling domains.
Fixes: isc-projects/bind9#5874
(cherry picked from commit 6e5066bb1f0f12d090e8707adb7d6ccf74f8012b)
(cherry picked from commit c9cb6a5e24e43489cf3fd4d4cc2193b6a74499cb)
---
lib/dns/dnssec.c | 19 +++++++++++++++++--
lib/isc/result.c | 2 +-
2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/lib/dns/dnssec.c b/lib/dns/dnssec.c
index b12529b5d5..9b9b1f2bb2 100644
--- a/lib/dns/dnssec.c
+++ b/lib/dns/dnssec.c
@@ -424,10 +424,25 @@ dns_dnssec_verify(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
}
/*
- * NS, SOA and DNSKEY records are signed by their owner.
- * DS records are signed by the parent.
+ * NS, SOA and DNSKEY records are signed by their owners.
+ * NSEC3 records are signed by the apex, exactly one level up
+ * from their owner names.
+ * DS records are signed by the parent zone.
*/
switch (set->type) {
+ case dns_rdatatype_nsec3: {
+ dns_name_t apex = DNS_NAME_INITEMPTY;
+ labels = dns_name_countlabels(name);
+ if (labels <= 1) {
+ inc_stat(dns_dnssecstats_fail);
+ return DNS_R_INVALIDNSEC3;
+ }
+ dns_name_split(name, labels - 1, NULL, &apex);
+ if (!dns_name_equal(&apex, &sig.signer)) {
+ inc_stat(dns_dnssecstats_fail);
+ return DNS_R_SIGINVALID;
+ }
+ } break;
case dns_rdatatype_ns:
case dns_rdatatype_soa:
case dns_rdatatype_dnskey:
diff --git a/lib/isc/result.c b/lib/isc/result.c
index 83e8cfeed7..b76c3d1f7b 100644
--- a/lib/isc/result.c
+++ b/lib/isc/result.c
@@ -198,7 +198,7 @@ static const char *description[ISC_R_NRESULTS] = {
[DNS_R_COVERINGNSEC] = "covering NSEC record returned",
[DNS_R_MXISADDRESS] = "MX is an address",
[DNS_R_DUPLICATE] = "duplicate query",
- [DNS_R_INVALIDNSEC3] = "invalid NSEC3 owner name (wildcard)",
+ [DNS_R_INVALIDNSEC3] = "invalid NSEC3 owner name",
[DNS_R_NOTPRIMARY] = "not primary",
[DNS_R_BROKENCHAIN] = "broken trust chain",
[DNS_R_EXPIRED] = "expired",
--
2.55.0

View file

@ -0,0 +1,320 @@
From a4ce4c0ce5b8d7630417730dc1b98bf554e0801f Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Tue, 19 May 2026 10:44:04 +1000
Subject: [PATCH] Check that dns_name_fromwire honours the active region
When reading DNS records from the wire the active region of the
source buffer is set to the end of the current record. dns_name_fromwire
should fail if it attempts to read past this setting.
(cherry picked from commit 3ed821d68b15fe4e6288e3054397d6bce7e65968)
(cherry picked from commit d413c9ac2e29a728531354a69c8c8234c01b7d1e)
Check that a short PRIVATEDNS record is rejected
A bug in dns_name_fromwire meant that short PRIVATEDNS key
records where being accepted. Test that this is no longer
the case.
(cherry picked from commit f48d48027384d8c2210b5ce9e3eac7af101ead3d)
(cherry picked from commit 19ac8b8e46aeb0a15e217bc7bdf485b31b87d9b4)
POC for PRIVATEDNS DNSKEY overrun not being detected
Construct a DNS message where a PRIVATEDNS DNSKEY identifier
overruns the record boundary by 3 byte so that the label ends
at the end of the compression pointer for the next record. The
next type is less than 256 so the next octet is 00 terminating
the identifier name. The transfered zone is then written to
disk using master-format text triggering the assertion when the
truncated identier is discovered.
Note this test will produce a false result in versions of
BIND that do not check the PRIVATEDNS identifier as it looks
for the error message when the transfer is aborted.
(cherry picked from commit 9ce3bce8bc8b4e9c6a9b1e84b5849c33eb27830e)
(cherry picked from commit 8e066d3fc369e3346f22bb5cfb67a7ab08a74034)
---
bin/tests/system/xfer/ans9/ans.py | 142 ++++++++++++++++++++++++
bin/tests/system/xfer/ns6/named.conf.in | 9 ++
bin/tests/system/xfer/tests.sh | 16 +++
tests/dns/name_test.c | 30 +++++
tests/dns/rdata_test.c | 21 ++++
5 files changed, 218 insertions(+)
create mode 100644 bin/tests/system/xfer/ans9/ans.py
diff --git a/bin/tests/system/xfer/ans9/ans.py b/bin/tests/system/xfer/ans9/ans.py
new file mode 100644
index 0000000000..a9e73953ee
--- /dev/null
+++ b/bin/tests/system/xfer/ans9/ans.py
@@ -0,0 +1,142 @@
+"""
+Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+
+SPDX-License-Identifier: MPL-2.0
+
+This Source Code Form is subject to the terms of the Mozilla Public
+License, v. 2.0. If a copy of the MPL was not distributed with this
+file, you can obtain one at https://mozilla.org/MPL/2.0/.
+
+See the COPYRIGHT file distributed with this work for additional
+information regarding copyright ownership.
+"""
+
+from collections.abc import AsyncGenerator
+
+import dns.name
+import dns.rcode
+import dns.rdatatype
+import dns.rrset
+
+from isctest.asyncserver import (
+ ControllableAsyncDnsServer,
+ DnsResponseSend,
+ DomainHandler,
+ QueryContext,
+ ResponseAction,
+ ToggleResponsesCommand,
+)
+
+
+class AXFRServer(DomainHandler):
+ """
+ Yield SOA and AXFR responses. Every new AXFR response increments the SOA
+ version.
+ """
+
+ domains = ["xfr-and-reconfig", "private-dns-overrun"]
+
+ def __init__(self) -> None:
+ super().__init__()
+ self.soa_version = 0
+
+ async def get_responses(
+ self, qctx: QueryContext
+ ) -> AsyncGenerator[ResponseAction, None]:
+ # This is oversimplified because I am lazy - we are appending the SOA
+ # RRset to the ANSWER section for _every_ QTYPE. named is only
+ # expected to send a SOA query over UDP and then an AXFR query over
+ # TCP. Responses to both of those start with a SOA RRset in the ANSWER
+ # section :-)
+ soa_message = qctx.response
+ soa_rrset = dns.rrset.from_text(
+ qctx.qname,
+ 300,
+ qctx.qclass,
+ dns.rdatatype.SOA,
+ f". . {self.soa_version} 0 0 0 0",
+ )
+ soa_message.answer.append(soa_rrset)
+
+ yield DnsResponseSend(soa_message)
+
+ if qctx.qtype == dns.rdatatype.SOA:
+ # If QTYPE=SOA, the SOA record is the complete response.
+ return
+
+ if qctx.qtype != dns.rdatatype.AXFR:
+ # If QTYPE=AXFR, we will continue cramming RRsets into the ANSWER
+ # section of a subsequent DNS message below.
+ #
+ # If QTYPE was not SOA or AXFR, abort. Yeah, we just sent a broken
+ # response by yielding DnsResponseSend() with a SOA RRset in the
+ # ANSWER section above. We will have to carry that burden for the
+ # rest of our lives.
+ return
+
+ # Send just the obligatory NS RRset at zone apex in the next message.
+ # This is stupidly inefficient, but makes looping below simpler as we
+ # will already have been done with the mandatory stuff by then.
+ ns_message = qctx.prepare_new_response()
+ ns_rrset = dns.rrset.from_text(
+ qctx.qname, 300, qctx.qclass, dns.rdatatype.NS, "."
+ )
+ ns_message.answer.append(ns_rrset)
+
+ yield DnsResponseSend(ns_message)
+
+ # Generate the AXFR with a txt rrset.
+ txt_message = qctx.prepare_new_response()
+ txt_rrset = dns.rrset.from_text(
+ qctx.qname,
+ 300,
+ qctx.qclass,
+ dns.rdatatype.TXT,
+ "foo bar",
+ )
+ txt_message.answer.append(txt_rrset)
+
+ yield DnsResponseSend(txt_message)
+
+ if qctx.qname == dns.name.from_text("private-dns-overrun"):
+ # A message where the malformed DNSKEY algorithm identifier
+ # finishes on a 00 byte in the next record. Assumes the
+ # next record starts with a compression pointer which is
+ # followed by the type which starts with 00.
+
+ # Generate malformed PRIVATE DNS DNSKEY
+ dnskey_message = qctx.prepare_new_response()
+ dnskey_rrset = dns.rrset.from_text(
+ qctx.qname,
+ 300,
+ qctx.qclass,
+ dns.rdatatype.DNSKEY,
+ "\\# 12 00 00 00 fd 09 00 00 00 00 00 00 00",
+ )
+ dnskey_message.answer.append(dnskey_rrset)
+ # Generate well formed PRIVATE DNS DNSKEY
+ dnskey_rrset = dns.rrset.from_text(
+ qctx.qname,
+ 300,
+ qctx.qclass,
+ dns.rdatatype.DNSKEY,
+ "\\# 12 00 00 00 fd 06 00 00 00 00 00 00 00",
+ )
+ dnskey_message.answer.append(dnskey_rrset)
+
+ yield DnsResponseSend(dnskey_message)
+
+ # Finish the AXFR transaction by sending the second SOA RRset.
+ yield DnsResponseSend(soa_message)
+
+ # This makes sure that the next SOA request causes a new zone transfer
+ self.soa_version += 1
+
+
+if __name__ == "__main__":
+ server = ControllableAsyncDnsServer(
+ default_aa=True, default_rcode=dns.rcode.NOERROR
+ )
+ server.install_control_command(ToggleResponsesCommand())
+ server.install_response_handler(AXFRServer())
+ server.run()
diff --git a/bin/tests/system/xfer/ns6/named.conf.in b/bin/tests/system/xfer/ns6/named.conf.in
index 142383c89a..63809448f0 100644
--- a/bin/tests/system/xfer/ns6/named.conf.in
+++ b/bin/tests/system/xfer/ns6/named.conf.in
@@ -83,3 +83,12 @@ zone "ixfr-too-big" {
primaries { 10.53.0.1; };
file "ixfr-too-big.bk";
};
+
+# GL#6004
+zone "private-dns-overrun" {
+ type secondary;
+ primaries { 10.53.0.9; };
+ file "private-dns-overrun.bk";
+ masterfile-format text; # force bug to be exercised
+ request-ixfr no; # ans9 supports only axfr
+};
diff --git a/bin/tests/system/xfer/tests.sh b/bin/tests/system/xfer/tests.sh
index a2c0adbc28..e08be175b7 100755
--- a/bin/tests/system/xfer/tests.sh
+++ b/bin/tests/system/xfer/tests.sh
@@ -622,5 +622,21 @@ if [ $tmp -eq 0 ]; then
fi
status=$((status + tmp))
+# def test_malformed_private_dns_identifier_overrun(ns6):
+# isctest.log.info(
+# "Check that a malformed PRIVATEDNS DNSKEY which overruns the record is rejected"
+# )
+# with ns6.watch_log_from_start(timeout=60) as watcher_transfer_completed:
+# watcher_transfer_completed.wait_for_line(
+# "zone private-dns-overrun/IN: zone transfer finished: unexpected end of input"
+# )
+n=$((n + 1))
+echo_i "Check that a malformed PRIVATEDNS DNSKEY which overruns the record is rejected ($n)"
+tmp=0
+nextpartreset ns6/named.run
+retry 60 wait_for_message "zone private-dns-overrun/IN: zone transfer finished: unexpected end of input" || tmp=1
+if test $tmp != 0; then echo_i "failed"; fi
+status=$((status + tmp))
+
echo_i "exit status: $status"
[ $status -eq 0 ] || exit 1
diff --git a/tests/dns/name_test.c b/tests/dns/name_test.c
index fb34dcace1..95f6598eb8 100644
--- a/tests/dns/name_test.c
+++ b/tests/dns/name_test.c
@@ -335,6 +335,35 @@ ISC_RUN_TEST_IMPL(fromregion) {
assert_false(dns_name_isabsolute(&name));
}
+ISC_RUN_TEST_IMPL(fromwire) {
+ dns_decompress_t dctx;
+ dns_fixedname_t fixed;
+ dns_name_t *name = dns_fixedname_initname(&fixed);
+ isc_buffer_t b;
+ unsigned char source[] = { 0x03, 'o', 'n', 'e', 0x00, 0x03,
+ 't', 'w', 'o', 0x00, 0x05, 't',
+ 'h', 'r', 'e', 'e', 0x00 };
+ isc_result_t result;
+
+ isc_buffer_init(&b, source, sizeof(source));
+ isc_buffer_add(&b, sizeof(source));
+ isc_buffer_setactive(&b, 10); /* names 'one.' and 'two.' */
+
+ /*
+ * We should only be able to read two names from the buffer
+ * as the active region has been set to cover only the first
+ * two.
+ */
+ dns_decompress_init(&dctx, -1, DNS_DECOMPRESS_STRICT);
+ dns_decompress_setmethods(&dctx, DNS_COMPRESS_NONE);
+ result = dns_name_fromwire(name, &b, &dctx, 0, NULL);
+ assert_int_equal(result, ISC_R_SUCCESS);
+ result = dns_name_fromwire(name, &b, &dctx, 0, NULL);
+ assert_int_equal(result, ISC_R_SUCCESS);
+ result = dns_name_fromwire(name, &b, &dctx, 0, NULL);
+ assert_int_not_equal(result, ISC_R_SUCCESS);
+}
+
/* is trust-anchor-telemetry test */
ISC_RUN_TEST_IMPL(istat) {
dns_fixedname_t fixed;
@@ -778,6 +807,7 @@ ISC_TEST_LIST_START
ISC_TEST_ENTRY(fullcompare)
ISC_TEST_ENTRY(compression)
ISC_TEST_ENTRY(fromregion)
+ISC_TEST_ENTRY(fromwire)
ISC_TEST_ENTRY(istat)
ISC_TEST_ENTRY(init)
ISC_TEST_ENTRY(invalidate)
diff --git a/tests/dns/rdata_test.c b/tests/dns/rdata_test.c
index 6354819d10..7f0df6e046 100644
--- a/tests/dns/rdata_test.c
+++ b/tests/dns/rdata_test.c
@@ -2199,6 +2199,27 @@ ISC_RUN_TEST_IMPL(key) {
check_rdata(NULL, wire_ok, NULL, false, dns_rdataclass_in,
dns_rdatatype_key, sizeof(dns_rdata_key_t));
+
+ /*
+ * A valid PRIVATEDNS record with an active region shorter than the
+ * actual record length. A bug in dns_name_fromwire meant that this
+ * was previously accepted.
+ */
+ dns_decompress_t dctx;
+ unsigned char key[] = { 0x00, 0x00, 0x00, 253, 0x07, 'e', 'x',
+ 'a', 'm', 'p', 'l', 'e', 0x00 };
+ unsigned char buf[sizeof(key)];
+ isc_buffer_t source, target;
+ isc_result_t result;
+
+ isc_buffer_init(&source, key, sizeof(key));
+ isc_buffer_add(&source, sizeof(key));
+ isc_buffer_setactive(&source, sizeof(key) - 1);
+ isc_buffer_init(&target, buf, sizeof(buf));
+ dns_decompress_init(&dctx, -1, DNS_DECOMPRESS_ANY);
+ result = dns_rdata_fromwire(NULL, dns_rdataclass_in, dns_rdatatype_key,
+ &source, &dctx, 0, &target);
+ assert_int_not_equal(result, ISC_R_SUCCESS);
}
/*
--
2.55.0

View file

@ -0,0 +1,54 @@
From 7596cbc240b0492461943f7c34d040fb66a7554c Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Tue, 19 May 2026 15:00:17 +1000
Subject: [PATCH] Fix the yaml query zone name code in dnstap-read
When the buffer to read the query zone name was constructed
isc_buffer_setactive was not called. This is now needed as
dns_name_fromwire is being corrected to check the active region.
(cherry picked from commit a25522c28c46655a81d2bf1d96374c81d834b157)
(cherry picked from commit a5f1a9d0d2ec021618924b14202ac96ead8299c1)
Fix dns_name_fromwire to honour the active region
dns_name_fromwire was not honouring the source buffer's active
region when reading names from the wire. This allowed malformed
records to be accepted when they shouldn't have been. This has
been corrected.
(cherry picked from commit 7c4f07a7ef6b571073327b02209df7f75b9363ff)
(cherry picked from commit e73b70a64453e7d97a11cb5f0afe8bb02d34aaf8)
---
bin/tools/dnstap-read.c | 1 +
lib/dns/name.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/bin/tools/dnstap-read.c b/bin/tools/dnstap-read.c
index a1d0243a1a..bb78ae12b1 100644
--- a/bin/tools/dnstap-read.c
+++ b/bin/tools/dnstap-read.c
@@ -298,6 +298,7 @@ print_yaml(dns_dtdata_t *dt) {
isc_buffer_init(&b, m->query_zone.data, m->query_zone.len);
isc_buffer_add(&b, m->query_zone.len);
+ isc_buffer_setactive(&b, m->query_zone.len);
dns_decompress_init(&dctx, -1, DNS_DECOMPRESS_NONE);
result = dns_name_fromwire(name, &b, &dctx, 0, NULL);
diff --git a/lib/dns/name.c b/lib/dns/name.c
index cc0e30e5b5..2ce868a2ba 100644
--- a/lib/dns/name.c
+++ b/lib/dns/name.c
@@ -1833,7 +1833,7 @@ dns_name_fromwire(dns_name_t *const name, isc_buffer_t *const source,
* The amount of the source we consumed is set once.
*/
const uint8_t *const source_buf = isc_buffer_base(source);
- const uint8_t *const source_max = isc_buffer_used(source);
+ const uint8_t *const source_max = isc_buffer_active(source);
const uint8_t *const start = isc_buffer_current(source);
const uint8_t *marker = start;
const uint8_t *cursor = start;
--
2.55.0

View file

@ -0,0 +1,69 @@
From cde8bb21e09205a7bd1f41fd07ed011fc80d8d71 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Fri, 10 Apr 2026 10:24:06 +1000
Subject: [PATCH] Fix TTL extraction from A/AAAA record
(cherry picked from commit 89c86e338db2492b92e6618c586f146c6928dc6d)
(cherry picked from commit adc8285d23e2eac6ec463f5dbc5a9596fdd36c60)
Check rpz name too long wildcard CNAME expansion handling
(cherry picked from commit 9345394e2097031b55b3ef34ceaadf5a7ebbeef2)
(cherry picked from commit 095b11f20f911f5b8059bdc349b256d6c64ece30)
---
bin/tests/system/rpz/ns2/tld2.db | 2 ++
bin/tests/system/rpz/ns4/tld4.db | 2 ++
bin/tests/system/rpz/tests.sh | 7 +++++--
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/bin/tests/system/rpz/ns2/tld2.db b/bin/tests/system/rpz/ns2/tld2.db
index c6f2556db5..c091ee27b7 100644
--- a/bin/tests/system/rpz/ns2/tld2.db
+++ b/bin/tests/system/rpz/ns2/tld2.db
@@ -123,3 +123,5 @@ a7-1 A 192.168.7.1
a7-2 A 192.168.7.2
TXT "a7-2 tld2 text"
+
+*.wild A 192.168.9.1
diff --git a/bin/tests/system/rpz/ns4/tld4.db b/bin/tests/system/rpz/ns4/tld4.db
index fca419c6dd..8accd76baf 100644
--- a/bin/tests/system/rpz/ns4/tld4.db
+++ b/bin/tests/system/rpz/ns4/tld4.db
@@ -59,6 +59,8 @@ a3-6.tld2 A 56.56.56.56
a3-7.sub1.tld2 A 57.57.57.57
+*.wild.sub1.tld2 A 57.57.57.57
+
a3-8.tld2 A 58.58.58.58
a3-9.sub9.tld2 A 59.59.59.59
diff --git a/bin/tests/system/rpz/tests.sh b/bin/tests/system/rpz/tests.sh
index 87e4118ca3..5297437694 100644
--- a/bin/tests/system/rpz/tests.sh
+++ b/bin/tests/system/rpz/tests.sh
@@ -391,7 +391,7 @@ addr() {
digcmd $2 >$DIGNM
#ckalive "$2" "server crashed by 'dig $2'" || return 1
ADDR_ESC=$(echo "$ADDR" | sed -e 's/\./\\./g')
- ADDR_TTL=$(sed -n -e "s/^[-.a-z0-9]\{1,\}[ ]*\([0-9]*\) IN AA* ${ADDR_ESC}\$/\1/p" $DIGNM)
+ ADDR_TTL=$(sed -n -e "s/^[-.a-z0-9]\{1,\}[ ]*\([0-9]*\)[ ]IN[ ]AA*[ ]${ADDR_ESC}\$/\1/p" $DIGNM)
if test -z "$ADDR_TTL"; then
setret "'dig $2' wrong; no address $ADDR record in $DIGNM"
return 0
@@ -516,7 +516,10 @@ nochange TCP a3-9.tld2 # 33 tcp-only
here x.servfail <<'EOF' # 34 qname-wait-recurse yes
;; status: SERVFAIL, x
EOF
-addr 35.35.35.35 "x.servfail @$ns5" # 35 qname-wait-recurse no
+addr 35.35.35.35 "x.servfail @$ns5" # 35 qname-wait-recurse no
+here aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.wild.sub1.tld2 <<'EOF' # 36 wildcard CNAME name to long
+ ;; status: YXDOMAIN, x
+EOF
end_group
ckstats $ns3 test1 ns3 22
ckstats $ns5 test1 ns5 1
--
2.55.0

View file

@ -0,0 +1,31 @@
From 49f4cc4e93f14f1d5b6a472124e6aa457167fede Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Fri, 10 Apr 2026 10:26:14 +1000
Subject: [PATCH] Properly handle rpz name to long wildcard expansion
Previously a self referential CNAME and the original address
record were returned. We now return a YXDOMAIN response.
(cherry picked from commit cfc4c4f69870ce492deaaa429453563d1621ded3)
(cherry picked from commit dc328a199f96222e0c30cc20b7b795bfc2c9b2e4)
---
lib/ns/query.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/ns/query.c b/lib/ns/query.c
index d3a10be9ba..3bd7daf79c 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -7591,7 +7591,8 @@ query_rpzcname(query_ctx_t *qctx, dns_name_t *cname) {
qctx->fname, NULL);
if (result == DNS_R_NAMETOOLONG) {
client->message->rcode = dns_rcode_yxdomain;
- } else if (result != ISC_R_SUCCESS) {
+ }
+ if (result != ISC_R_SUCCESS) {
return result;
}
} else {
--
2.55.0

View file

@ -0,0 +1,280 @@
From d7e1f4495d6bac8c29b332e04e9b27140339375b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@sury.org>
Date: Tue, 23 Jun 2026 10:59:38 +0200
Subject: [PATCH] Make the dns_slabheaders in the cache reference counted
Instead of only reference counting the enclosing qpcnode, add the
reference counting directly to the slabheaders. The reference is
incremented when an rdataset is bound to the header and decremented when
the rdataset is disassociated, so a stale slabheader can be removed from
the node's down chain as soon as its own reference count reaches zero,
instead of waiting for the whole qpcnode to become unreferenced.
Building on that, clean up the ancient headers eagerly: mark_ancient()
is made idempotent, releases the header's own (container) reference and
reaps the stale headers from the node's down chain as soon as their
references reach zero. A header evicted over the per-name type limit is
expired only after the new rdataset has been bound, so the bind's
increment always precedes mark_ancient()'s decrement.
Because a header can now be reclaimed independently of its node, the
rdataset iterators must keep the header they are positioned on alive:
each iterator takes a reference on its current header and releases it
when it advances or is destroyed. Iteration otherwise stays lazy and
re-reads the node on every step, so it still observes records added to
the node while the iterator is live, as zone signing requires.
The slab headers are shared with the zone databases, so the matching
increment is added to every bind path. The noqname/closest proofs hand
out rdatasets backed by bare slabs that have no header, so they are
given a separate dns_rdataproof_rdatasetmethods that leaves the
reference count untouched.
(cherry picked from commit 2dabf117e1264fd13fb33096f87e78a039fd1c6c)
(cherry picked from commit 231b1ca3edfb26389e1af39181aa6b4413e87ec4)
---
bin/tests/system/reclimit/tests.sh | 4 +-
lib/dns/include/dns/rdataslab.h | 1 +
lib/dns/rbtdb.c | 77 +++++++++++++++++++++++++-----
3 files changed, 69 insertions(+), 13 deletions(-)
diff --git a/bin/tests/system/reclimit/tests.sh b/bin/tests/system/reclimit/tests.sh
index c15225488f..55ccac7759 100644
--- a/bin/tests/system/reclimit/tests.sh
+++ b/bin/tests/system/reclimit/tests.sh
@@ -338,13 +338,13 @@ echo_i "checking that NXDOMAIN names over the max-types-per-name limit don't get
# Query for 10 NXDOMAIN types
for ntype in $(seq 65270 65279); do
- check_manytypes 1 manytypes.big "TYPE${ntype}" NOERROR big SOA 0 || ret=1
+ check_manytypes 1 manytypes.big "TYPE${ntype}" NOERROR big SOA 120 || ret=1
done
# Wait at least 1 second
sleep 1
# Query for 10 NXDOMAIN types again - these should not be cached
for ntype in $(seq 65270 65279); do
- check_manytypes 2 manytypes.big "TYPE${ntype}" NOERROR big SOA 0 || ret=1
+ check_manytypes 2 manytypes.big "TYPE${ntype}" NOERROR big SOA 120 || ret=1
done
if [ $ret -ne 0 ]; then echo_i "failed"; fi
diff --git a/lib/dns/include/dns/rdataslab.h b/lib/dns/include/dns/rdataslab.h
index 5729c004ca..6bd3b5997d 100644
--- a/lib/dns/include/dns/rdataslab.h
+++ b/lib/dns/include/dns/rdataslab.h
@@ -44,6 +44,7 @@
#include <stdbool.h>
#include <isc/lang.h>
+#include <isc/refcount.h>
#include <dns/types.h>
diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 62bc97d783..0b8547950f 100644
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -158,6 +158,7 @@ struct noqname {
};
typedef struct rdatasetheader {
+ isc_refcount_t references;
/*%
* Locked by the owning node's lock.
*/
@@ -1447,6 +1448,7 @@ init_rdataset(dns_rbtdb_t *rbtdb, rdatasetheader_t *h) {
h->heap_index = 0;
atomic_init(&h->attributes, 0);
atomic_init(&h->last_refresh_fail_ts, 0);
+ isc_refcount_init(&h->references, 1);
STATIC_ASSERT(sizeof(h->attributes) == 2,
"The .attributes field of rdatasetheader_t needs to be "
@@ -1559,6 +1561,9 @@ rollback_node(dns_rbtnode_t *node, rbtdb_serial_t serial) {
}
}
+static void
+clean_stale_headers(dns_rbtdb_t *rbtdb, isc_mem_t *mctx, rdatasetheader_t *top);
+
static void
mark_header_ancient(dns_rbtdb_t *rbtdb, rdatasetheader_t *header) {
uint_least16_t attributes = atomic_load_acquire(&header->attributes);
@@ -1584,8 +1589,12 @@ mark_header_ancient(dns_rbtdb_t *rbtdb, rdatasetheader_t *header) {
update_rrsetstats(rbtdb, header->type, attributes, false);
header->node->dirty = 1;
+ isc_refcount_decrement(&header->references);
+
/* Increment the stats counter for the ancient RRtype. */
update_rrsetstats(rbtdb, header->type, newattributes, true);
+
+ clean_stale_headers(rbtdb, rbtdb->common.mctx, header);
}
static void
@@ -1621,12 +1630,19 @@ static void
clean_stale_headers(dns_rbtdb_t *rbtdb, isc_mem_t *mctx,
rdatasetheader_t *top) {
rdatasetheader_t *d, *down_next;
+ rdatasetheader_t *down_parent = top;
for (d = top->down; d != NULL; d = down_next) {
down_next = d->down;
- free_rdataset(rbtdb, mctx, d);
+ d->next = down_parent;
+
+ if (isc_refcount_current(&d->references) == 0) {
+ free_rdataset(rbtdb, mctx, d);
+ down_parent->down = down_next;
+ } else {
+ down_parent = d;
+ }
}
- top->down = NULL;
}
static void
@@ -1642,6 +1658,7 @@ clean_cache_node(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node) {
for (current = node->data; current != NULL; current = top_next) {
top_next = current->next;
clean_stale_headers(rbtdb, mctx, current);
+ INSIST(current->down == NULL);
/*
* If current is nonexistent, ancient, or stale and
* we are not keeping stale, we can clean it up.
@@ -3114,6 +3131,8 @@ bind_rdataset(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rdatasetheader_t *header,
return;
}
+ isc_refcount_increment(&header->references);
+
dns__rbtnode_acquire(rbtdb, node, locktype);
INSIST(rdataset->methods == NULL); /* We must be disassociated. */
@@ -6307,6 +6326,7 @@ add32(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, const dns_name_t *nodename,
bool header_nx;
bool newheader_nx;
bool merge;
+ bool do_expireheader = false;
dns_rdatatype_t rdtype, covers;
rbtdb_rdatatype_t negtype, sigtype;
dns_trust_t trust;
@@ -6856,6 +6876,7 @@ find_header:
}
if (IS_CACHE(rbtdb) && overmaxtype(rbtdb, ntypes)) {
+ do_expireheader = true;
if (expireheader == NULL) {
expireheader = newheader;
}
@@ -6869,15 +6890,6 @@ find_header:
*/
expireheader = newheader;
}
-
- set_ttl(rbtdb, expireheader, 0);
- mark_header_ancient(rbtdb, expireheader);
- /*
- * FIXME: In theory, we should mark the RRSIG
- * and the header at the same time, but there is
- * no direct link between those two header, so
- * we would have to check the whole list again.
- */
}
}
}
@@ -6901,6 +6913,15 @@ find_header:
isc_rwlocktype_write, addedrdataset);
}
+ /*
+ * We need to delay the expiration of the header until we are bound to
+ * it to prevent decrement-then-increment on the header references.
+ */
+ if (do_expireheader) {
+ set_ttl(rbtdb, expireheader, 0);
+ mark_header_ancient(rbtdb, expireheader);
+ }
+
return ISC_R_SUCCESS;
}
@@ -8692,6 +8713,12 @@ rdataset_disassociate(dns_rdataset_t *rdataset) {
dns_db_t *db = rdataset->private1;
dns_dbnode_t *node = rdataset->private2;
+ if (rdataset->methods == &rdataset_methods) {
+ rdatasetheader_t *header = rdataset->private3;
+ header--;
+ isc_refcount_decrement(&header->references);
+ }
+
detachnode(db, &node);
}
@@ -8806,6 +8833,11 @@ rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target) {
dns_dbnode_t *cloned_node = NULL;
attachnode(db, node, &cloned_node);
+ if (source->methods == &rdataset_methods) {
+ rdatasetheader_t *header = source->private3;
+ header--;
+ isc_refcount_increment(&header->references);
+ }
INSIST(!ISC_LINK_LINKED(target, link));
*target = *source;
ISC_LINK_INIT(target, link);
@@ -8969,6 +9001,11 @@ rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp) {
rbtiterator = (rbtdb_rdatasetiter_t *)(*iteratorp);
+ if (rbtiterator->current != NULL) {
+ isc_refcount_decrement(&rbtiterator->current->references);
+ rbtiterator->current = NULL;
+ }
+
if (rbtiterator->common.version != NULL) {
closeversion(rbtiterator->common.db,
&rbtiterator->common.version, false);
@@ -9046,9 +9083,18 @@ rdatasetiter_first(dns_rdatasetiter_t *iterator) {
}
}
+ if (header != NULL) {
+ isc_refcount_increment0(&header->references);
+ }
+
NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
isc_rwlocktype_read);
+ if (rbtiterator->current != NULL) {
+ isc_refcount_decrement(&rbtiterator->current->references);
+ rbtiterator->current = NULL;
+ }
+
rbtiterator->current = header;
if (header == NULL) {
@@ -9140,9 +9186,18 @@ rdatasetiter_next(dns_rdatasetiter_t *iterator) {
}
}
+ if (header != NULL) {
+ isc_refcount_increment0(&header->references);
+ }
+
NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
isc_rwlocktype_read);
+ if (rbtiterator->current != NULL) {
+ isc_refcount_decrement(&rbtiterator->current->references);
+ rbtiterator->current = NULL;
+ }
+
rbtiterator->current = header;
if (header == NULL) {
--
2.55.0

View file

@ -0,0 +1,144 @@
From b08e0876639ab9f3dae3813202861fd1098f2611 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Tue, 14 Apr 2026 13:46:22 +1000
Subject: [PATCH] Test RRSIG record parsing
In particular test that labels and signer fields are consistent.
(cherry picked from commit 5a95e64731afe63d348d272cc4d3b2f9847150c2)
(cherry picked from commit 19e496ca260b6a756ae1378e8ebcbdb666b7d9ed)
---
tests/dns/rdata_test.c | 110 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 110 insertions(+)
diff --git a/tests/dns/rdata_test.c b/tests/dns/rdata_test.c
index 7f0df6e046..c704d98ed1 100644
--- a/tests/dns/rdata_test.c
+++ b/tests/dns/rdata_test.c
@@ -2504,6 +2504,115 @@ ISC_RUN_TEST_IMPL(rkey) {
dns_rdatatype_rkey, sizeof(dns_rdata_rkey_t));
}
+ISC_RUN_TEST_IMPL(rrsig) {
+ text_ok_t text_ok[] = {
+ TEXT_VALID("SOA 8 0 86400 20260426170000 20260413160000 54393 "
+ ". "
+ "tFbcoVP8MnpecUquJ/aj+XeNgV7ts9GSHVkXaXRJrJ/"
+ "TEkOZApVG0F6E "
+ "9sYpxGk2ItweLL43ujioGj0HWwZDRR+vbur+O/"
+ "dIdheiig1VvU+9HXLi "
+ "QOViY9Kc64ixdyJhYCC5K+bO1qsHxd+"
+ "KJXOaxyHbqchYkDFy4PL6qftE "
+ "VaLkueRgjXgOsq/"
+ "NxvCXDgAa5xy0+3Sl0myxIs8rJ5KeXfJQFe7qxgaw "
+ "VjJsJTKw8neOTw2rQfLaigWu2LIWw+"
+ "IyVrLjZJdLqGkiLBGd1w4X3U12 "
+ "fFxoY3eqzNgBEtduoGKPZ/"
+ "NpP9cuKJORJ18283aV8hR4WO91VR0q1zcM jLwqUg=="),
+ /* labels too short for signer */
+ TEXT_INVALID("SOA 8 0 86400 20260426170000 20260413160000 "
+ "54393 example. "
+ "tFbcoVP8MnpecUquJ/aj+XeNgV7ts9GSHVkXaXRJrJ/"
+ "TEkOZApVG0F6E "
+ "9sYpxGk2ItweLL43ujioGj0HWwZDRR+vbur+O/"
+ "dIdheiig1VvU+9HXLi "
+ "QOViY9Kc64ixdyJhYCC5K+bO1qsHxd+"
+ "KJXOaxyHbqchYkDFy4PL6qftE "
+ "VaLkueRgjXgOsq/"
+ "NxvCXDgAa5xy0+3Sl0myxIs8rJ5KeXfJQFe7qxgaw "
+ "VjJsJTKw8neOTw2rQfLaigWu2LIWw+"
+ "IyVrLjZJdLqGkiLBGd1w4X3U12 "
+ "fFxoY3eqzNgBEtduoGKPZ/"
+ "NpP9cuKJORJ18283aV8hR4WO91VR0q1zcM jLwqUg=="),
+ /*
+ * Sentinel.
+ */
+ TEXT_SENTINEL()
+ };
+ wire_ok_t wire_ok[] = {
+ WIRE_VALID(0x00, 0x06, 0x08, 0x00, 0x00, 0x01, 0x51, 0x80, 0x69,
+ 0xee, 0x44, 0x90, 0x69, 0xdd, 0x13, 0x00, 0xd4, 0x79,
+ 0x00, 0xb4, 0x56, 0xdc, 0xa1, 0x53, 0xfc, 0x32, 0x7a,
+ 0x5e, 0x71, 0x4a, 0xae, 0x27, 0xf6, 0xa3, 0xf9, 0x77,
+ 0x8d, 0x81, 0x5e, 0xed, 0xb3, 0xd1, 0x92, 0x1d, 0x59,
+ 0x17, 0x69, 0x74, 0x49, 0xac, 0x9f, 0xd3, 0x12, 0x43,
+ 0x99, 0x02, 0x95, 0x46, 0xd0, 0x5e, 0x84, 0xf6, 0xc6,
+ 0x29, 0xc4, 0x69, 0x36, 0x22, 0xdc, 0x1e, 0x2c, 0xbe,
+ 0x37, 0xba, 0x38, 0xa8, 0x1a, 0x3d, 0x07, 0x5b, 0x06,
+ 0x43, 0x45, 0x1f, 0xaf, 0x6e, 0xea, 0xfe, 0x3b, 0xf7,
+ 0x48, 0x76, 0x17, 0xa2, 0x8a, 0x0d, 0x55, 0xbd, 0x4f,
+ 0xbd, 0x1d, 0x72, 0xe2, 0x40, 0xe5, 0x62, 0x63, 0xd2,
+ 0x9c, 0xeb, 0x88, 0xb1, 0x77, 0x22, 0x61, 0x60, 0x20,
+ 0xb9, 0x2b, 0xe6, 0xce, 0xd6, 0xab, 0x07, 0xc5, 0xdf,
+ 0x8a, 0x25, 0x73, 0x9a, 0xc7, 0x21, 0xdb, 0xa9, 0xc8,
+ 0x58, 0x90, 0x31, 0x72, 0xe0, 0xf2, 0xfa, 0xa9, 0xfb,
+ 0x44, 0x55, 0xa2, 0xe4, 0xb9, 0xe4, 0x60, 0x8d, 0x78,
+ 0x0e, 0xb2, 0xaf, 0xcd, 0xc6, 0xf0, 0x97, 0x0e, 0x00,
+ 0x1a, 0xe7, 0x1c, 0xb4, 0xfb, 0x74, 0xa5, 0xd2, 0x6c,
+ 0xb1, 0x22, 0xcf, 0x2b, 0x27, 0x92, 0x9e, 0x5d, 0xf2,
+ 0x50, 0x15, 0xee, 0xea, 0xc6, 0x06, 0xb0, 0x56, 0x32,
+ 0x6c, 0x25, 0x32, 0xb0, 0xf2, 0x77, 0x8e, 0x4f, 0x0d,
+ 0xab, 0x41, 0xf2, 0xda, 0x8a, 0x05, 0xae, 0xd8, 0xb2,
+ 0x16, 0xc3, 0xe2, 0x32, 0x56, 0xb2, 0xe3, 0x64, 0x97,
+ 0x4b, 0xa8, 0x69, 0x22, 0x2c, 0x11, 0x9d, 0xd7, 0x0e,
+ 0x17, 0xdd, 0x4d, 0x76, 0x7c, 0x5c, 0x68, 0x63, 0x77,
+ 0xaa, 0xcc, 0xd8, 0x01, 0x12, 0xd7, 0x6e, 0xa0, 0x62,
+ 0x8f, 0x67, 0xf3, 0x69, 0x3f, 0xd7, 0x2e, 0x28, 0x93,
+ 0x91, 0x27, 0x5f, 0x36, 0xf3, 0x76, 0x95, 0xf2, 0x14,
+ 0x78, 0x58, 0xef, 0x75, 0x55, 0x1d, 0x2a, 0xd7, 0x37,
+ 0x0c, 0x8c, 0xbc, 0x2a, 0x52),
+ /* labels too short for signer */
+ WIRE_INVALID(
+ 0x00, 0x06, 0x08, 0x00, 0x00, 0x01, 0x51, 0x80, 0x69,
+ 0xee, 0x44, 0x90, 0x69, 0xdd, 0x13, 0x00, 0xd4, 0x79,
+ 0x07, 0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x00,
+ 0xb4, 0x56, 0xdc, 0xa1, 0x53, 0xfc, 0x32, 0x7a, 0x5e,
+ 0x71, 0x4a, 0xae, 0x27, 0xf6, 0xa3, 0xf9, 0x77, 0x8d,
+ 0x81, 0x5e, 0xed, 0xb3, 0xd1, 0x92, 0x1d, 0x59, 0x17,
+ 0x69, 0x74, 0x49, 0xac, 0x9f, 0xd3, 0x12, 0x43, 0x99,
+ 0x02, 0x95, 0x46, 0xd0, 0x5e, 0x84, 0xf6, 0xc6, 0x29,
+ 0xc4, 0x69, 0x36, 0x22, 0xdc, 0x1e, 0x2c, 0xbe, 0x37,
+ 0xba, 0x38, 0xa8, 0x1a, 0x3d, 0x07, 0x5b, 0x06, 0x43,
+ 0x45, 0x1f, 0xaf, 0x6e, 0xea, 0xfe, 0x3b, 0xf7, 0x48,
+ 0x76, 0x17, 0xa2, 0x8a, 0x0d, 0x55, 0xbd, 0x4f, 0xbd,
+ 0x1d, 0x72, 0xe2, 0x40, 0xe5, 0x62, 0x63, 0xd2, 0x9c,
+ 0xeb, 0x88, 0xb1, 0x77, 0x22, 0x61, 0x60, 0x20, 0xb9,
+ 0x2b, 0xe6, 0xce, 0xd6, 0xab, 0x07, 0xc5, 0xdf, 0x8a,
+ 0x25, 0x73, 0x9a, 0xc7, 0x21, 0xdb, 0xa9, 0xc8, 0x58,
+ 0x90, 0x31, 0x72, 0xe0, 0xf2, 0xfa, 0xa9, 0xfb, 0x44,
+ 0x55, 0xa2, 0xe4, 0xb9, 0xe4, 0x60, 0x8d, 0x78, 0x0e,
+ 0xb2, 0xaf, 0xcd, 0xc6, 0xf0, 0x97, 0x0e, 0x00, 0x1a,
+ 0xe7, 0x1c, 0xb4, 0xfb, 0x74, 0xa5, 0xd2, 0x6c, 0xb1,
+ 0x22, 0xcf, 0x2b, 0x27, 0x92, 0x9e, 0x5d, 0xf2, 0x50,
+ 0x15, 0xee, 0xea, 0xc6, 0x06, 0xb0, 0x56, 0x32, 0x6c,
+ 0x25, 0x32, 0xb0, 0xf2, 0x77, 0x8e, 0x4f, 0x0d, 0xab,
+ 0x41, 0xf2, 0xda, 0x8a, 0x05, 0xae, 0xd8, 0xb2, 0x16,
+ 0xc3, 0xe2, 0x32, 0x56, 0xb2, 0xe3, 0x64, 0x97, 0x4b,
+ 0xa8, 0x69, 0x22, 0x2c, 0x11, 0x9d, 0xd7, 0x0e, 0x17,
+ 0xdd, 0x4d, 0x76, 0x7c, 0x5c, 0x68, 0x63, 0x77, 0xaa,
+ 0xcc, 0xd8, 0x01, 0x12, 0xd7, 0x6e, 0xa0, 0x62, 0x8f,
+ 0x67, 0xf3, 0x69, 0x3f, 0xd7, 0x2e, 0x28, 0x93, 0x91,
+ 0x27, 0x5f, 0x36, 0xf3, 0x76, 0x95, 0xf2, 0x14, 0x78,
+ 0x58, 0xef, 0x75, 0x55, 0x1d, 0x2a, 0xd7, 0x37, 0x0c,
+ 0x8c, 0xbc, 0x2a, 0x52),
+
+ WIRE_SENTINEL()
+ };
+ check_rdata(text_ok, wire_ok, NULL, false, dns_rdataclass_in,
+ dns_rdatatype_rrsig, sizeof(dns_rdata_rrsig_t));
+}
+
ISC_RUN_TEST_IMPL(resinfo) {
text_ok_t text_ok[] = {
TEXT_VALID_CHANGED("qnamemin exterr=15,16,17 "
@@ -3357,6 +3466,7 @@ ISC_TEST_ENTRY(nsec3)
ISC_TEST_ENTRY(nxt)
ISC_TEST_ENTRY(resinfo)
ISC_TEST_ENTRY(rkey)
+ISC_TEST_ENTRY(rrsig)
ISC_TEST_ENTRY(sshfp)
ISC_TEST_ENTRY(wallet)
ISC_TEST_ENTRY(wks)
--
2.55.0

View file

@ -0,0 +1,267 @@
From 7a8a1f74c742e98fb5e105b013e7c2bd7af4a76c Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Tue, 14 Apr 2026 15:14:06 +1000
Subject: [PATCH] Don't sign out of zone records in dnssec-signzone
dnssec-signzone was signing extraneous records that were not within
the namespace of the zone. This no longer occurs.
(cherry picked from commit e45c9af7051421fd370f20ba8325199c606223fd)
Don't sign out of zone records in dnssec-signzone
dnssec-signzone was signing extraneous records that were not within
the namespace of the zone. This no longer occurs.
(cherry picked from commit e45c9af7051421fd370f20ba8325199c606223fd)
(cherry picked from commit 1a4986e2533f87e80eb21da3f06708d335aff1e2)
Invalid signed wildcard records were being accepted
An RRSIG whose Labels field indicates fewer labels than its signer
name requires was being accepted. When such a record covers a
wildcard, the validator reconstructs a wildcard owner name above the
signer's zone and caches it as secure. RFC 8198 cache synthesis
(synth-from-dnssec) then serves that forged wildcard for unrelated
names, poisoning the cache.
These records are now rejected, both when an RRSIG is parsed and when
its signature is verified.
(cherry picked from commit 084ca5ee10515e461d46b63df9660b8394bc7de9)
(cherry picked from commit 15089066b15f826d7487c3d160b5872820f84b83)
---
bin/dnssec/dnssec-signzone.c | 5 ++++
lib/dns/dnssec.c | 43 +++++++++++++++++++++++---------
lib/dns/rdata/generic/rrsig_46.c | 37 ++++++++++++++++++++-------
3 files changed, 64 insertions(+), 21 deletions(-)
diff --git a/bin/dnssec/dnssec-signzone.c b/bin/dnssec/dnssec-signzone.c
index 73855e6284..9e3a48a592 100644
--- a/bin/dnssec/dnssec-signzone.c
+++ b/bin/dnssec/dnssec-signzone.c
@@ -1643,6 +1643,11 @@ assignwork(isc_task_t *task, isc_task_t *worker) {
dns_db_detachnode(gdb, &node);
goto next;
}
+ if (!dns_name_issubdomain(name, gorigin)) {
+ dumpnode(name, node);
+ dns_db_detachnode(gdb, &node);
+ goto next;
+ }
/*
* Sort the zone data from the glue and out-of-zone data.
* For NSEC zones nodes with zone data have NSEC records.
diff --git a/lib/dns/dnssec.c b/lib/dns/dnssec.c
index c7e922437c..b12529b5d5 100644
--- a/lib/dns/dnssec.c
+++ b/lib/dns/dnssec.c
@@ -130,11 +130,11 @@ dns_dnssec_keyfromrdata(const dns_name_t *name, const dns_rdata_t *rdata,
isc_buffer_t b;
isc_region_t r;
- INSIST(name != NULL);
- INSIST(rdata != NULL);
- INSIST(mctx != NULL);
- INSIST(key != NULL);
- INSIST(*key == NULL);
+ REQUIRE(name != NULL);
+ REQUIRE(rdata != NULL);
+ REQUIRE(mctx != NULL);
+ REQUIRE(key != NULL);
+ REQUIRE(*key == NULL);
REQUIRE(rdata->type == dns_rdatatype_key ||
rdata->type == dns_rdatatype_dnskey);
@@ -187,12 +187,14 @@ dns_dnssec_sign(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
isc_result_t ret;
isc_buffer_t *databuf = NULL;
char data[256 + 8];
+ unsigned int labels;
unsigned int sigsize;
dns_fixedname_t fnewname;
dns_fixedname_t fsigner;
REQUIRE(name != NULL);
- REQUIRE(dns_name_countlabels(name) <= 255);
+ labels = dns_name_countlabels(name);
+ REQUIRE(labels <= 255 && labels > 0);
REQUIRE(set != NULL);
REQUIRE(key != NULL);
REQUIRE(inception != NULL);
@@ -221,7 +223,7 @@ dns_dnssec_sign(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
sig.covered = set->type;
sig.algorithm = dst_key_alg(key);
- sig.labels = dns_name_countlabels(name) - 1;
+ sig.labels = labels - 1;
if (dns_name_iswildcard(name)) {
sig.labels--;
}
@@ -365,10 +367,13 @@ dns_dnssec_verify(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
isc_result_t ret;
unsigned char data[300];
dst_context_t *ctx = NULL;
- int labels = 0;
+ unsigned int labels;
+ unsigned int siglabels;
bool downcase = false;
REQUIRE(name != NULL);
+ labels = dns_name_countlabels(name);
+ REQUIRE(labels > 0);
REQUIRE(set != NULL);
REQUIRE(key != NULL);
REQUIRE(mctx != NULL);
@@ -383,6 +388,21 @@ dns_dnssec_verify(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
return DNS_R_SIGINVALID;
}
+ /*
+ * The RRSIG labels field can't indicate fewer labels than the
+ * signer. Also the labels shouldn't be greater than that of
+ * the owner name.
+ *
+ * sig.labels doesn't include the root label, so add 1 to account
+ * for it.
+ */
+ siglabels = sig.labels + 1;
+ if (siglabels < dns_name_countlabels(&sig.signer) || siglabels > labels)
+ {
+ inc_stat(dns_dnssecstats_fail);
+ return DNS_R_SIGINVALID;
+ }
+
if (isc_serial_lt(sig.timeexpire, sig.timesigned)) {
inc_stat(dns_dnssecstats_fail);
return DNS_R_SIGINVALID;
@@ -449,10 +469,9 @@ again:
* If the name is an expanded wildcard, use the wildcard name.
*/
dns_fixedname_init(&fnewname);
- labels = dns_name_countlabels(name) - 1;
RUNTIME_CHECK(dns_name_downcase(name, dns_fixedname_name(&fnewname),
NULL) == ISC_R_SUCCESS);
- if (labels - sig.labels > 0) {
+ if (labels > siglabels) {
dns_name_split(dns_fixedname_name(&fnewname), sig.labels + 1,
NULL, dns_fixedname_name(&fnewname));
}
@@ -463,7 +482,7 @@ again:
* Create an envelope for each rdata: <name|type|class|ttl>.
*/
isc_buffer_init(&envbuf, data, sizeof(data));
- if (labels - sig.labels > 0) {
+ if (labels > siglabels) {
isc_buffer_putuint8(&envbuf, 1);
isc_buffer_putuint8(&envbuf, '*');
memmove(data + 2, r.base, r.length);
@@ -559,7 +578,7 @@ cleanup_struct:
inc_stat(dns_dnssecstats_fail);
}
- if (ret == ISC_R_SUCCESS && labels - sig.labels > 0) {
+ if (ret == ISC_R_SUCCESS && labels > siglabels) {
if (wild != NULL) {
RUNTIME_CHECK(dns_name_concatenate(
dns_wildcardname,
diff --git a/lib/dns/rdata/generic/rrsig_46.c b/lib/dns/rdata/generic/rrsig_46.c
index 10bc039e93..4cf4259c2b 100644
--- a/lib/dns/rdata/generic/rrsig_46.c
+++ b/lib/dns/rdata/generic/rrsig_46.c
@@ -23,12 +23,12 @@
static isc_result_t
fromtext_rrsig(ARGS_FROMTEXT) {
isc_token_t token;
- unsigned char c;
+ unsigned char alg, labels;
long i;
dns_rdatatype_t covered;
- char *e;
+ char *e = NULL;
isc_result_t result;
- dns_name_t name;
+ dns_name_t signer;
isc_buffer_t buffer;
uint32_t time_signed, time_expire;
@@ -61,8 +61,8 @@ fromtext_rrsig(ARGS_FROMTEXT) {
*/
RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_string,
false));
- RETTOK(dns_secalg_fromtext(&c, &token.value.as_textregion));
- RETERR(mem_tobuffer(target, &c, 1));
+ RETTOK(dns_secalg_fromtext(&alg, &token.value.as_textregion));
+ RETERR(mem_tobuffer(target, &alg, 1));
/*
* Labels.
@@ -72,8 +72,8 @@ fromtext_rrsig(ARGS_FROMTEXT) {
if (token.value.as_ulong > 0xffU) {
RETTOK(ISC_R_RANGE);
}
- c = (unsigned char)token.value.as_ulong;
- RETERR(mem_tobuffer(target, &c, 1));
+ labels = (unsigned char)token.value.as_ulong;
+ RETERR(mem_tobuffer(target, &labels, 1));
/*
* Original ttl.
@@ -144,12 +144,20 @@ fromtext_rrsig(ARGS_FROMTEXT) {
*/
RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_string,
false));
- dns_name_init(&name, NULL);
+ dns_name_init(&signer, NULL);
buffer_fromregion(&buffer, &token.value.as_region);
if (origin == NULL) {
origin = dns_rootname;
}
- RETTOK(dns_name_fromtext(&name, &buffer, origin, options, target));
+ RETTOK(dns_name_fromtext(&signer, &buffer, origin, options, target));
+
+ /*
+ * (RRSIG labels doesn't include the root label, so add one
+ * to normalize it before checking against the signer.)
+ */
+ if ((unsigned int)(labels + 1) < dns_name_countlabels(&signer)) {
+ RETTOK(ISC_R_RANGE);
+ }
/*
* Sig.
@@ -278,6 +286,7 @@ static isc_result_t
fromwire_rrsig(ARGS_FROMWIRE) {
isc_region_t sr;
dns_name_t name;
+ unsigned char labels;
REQUIRE(type == dns_rdatatype_rrsig);
@@ -300,6 +309,8 @@ fromwire_rrsig(ARGS_FROMWIRE) {
return ISC_R_UNEXPECTEDEND;
}
+ labels = sr.base[3];
+
isc_buffer_forward(source, 18);
RETERR(mem_tobuffer(target, sr.base, 18));
@@ -309,6 +320,14 @@ fromwire_rrsig(ARGS_FROMWIRE) {
dns_name_init(&name, NULL);
RETERR(dns_name_fromwire(&name, source, dctx, options, target));
+ /*
+ * (RRSIG labels doesn't include the root label, so add one
+ * to normalize it before checking against the signer.)
+ */
+ if ((unsigned int)(labels + 1) < dns_name_countlabels(&name)) {
+ RETERR(DNS_R_FORMERR);
+ }
+
/*
* Sig.
*/
--
2.55.0

View file

@ -0,0 +1,435 @@
From a31296b120efc985fb1fc3c932882e965156473b Mon Sep 17 00:00:00 2001
From: Colin Vidal <colin@isc.org>
Date: Mon, 15 Jun 2026 11:34:08 +0200
Subject: [PATCH] Reproducer for #5946 (assertion in some CNAME/DNAME queries)
Add a system test reproducing the issue reported by #5946, which
is also CVE-2026-12617. There are two scenarios:
- A client send queries for a DNAME and A record to the resolver (ns3),
and the authoritative server (ans2) responds positively to the A query
but delay the DNAME response and respond later negatively;
- A client send queries for a CNAME and A record to the resolver (ns3),
and the authoritative server (ans2) responds positively to the A query
but delay the CNAME response and respond later with a self-referential
CNAME.
The test does not check the results of the queries, however, it expects
the resolver to correctly handle those and do not assert.
(cherry picked from commit e88271f2e584010157b068cc998dd76451273562)
(cherry picked from commit bb92832fb6ae899bee7206c2d8966258461c2f71)
Stabilize timing in the cname_dname_negcache test
The #5946 reproducer relied on ans2 answering the negative DNAME/CNAME
query a fixed second after receiving it, racing that delay against the
resolver's per-query timeout. When the timeout fired first -- which
happens under load, most notably under ThreadSanitizer, where named is
slowed but ans2 (wall-clock) is not -- the resolver dropped the late
answer, never processed the negative response, and the watched SOA never
appeared, so the test timed out. This made it flaky on the
security-bind-9.20 CI. Merely shortening the fixed delay would trade
that for the opposite, worse failure: the negative answer arriving
before the positive one is cached, silently not exercising the bug.
Release the negative answer based on the resolver's progress instead of
a wall-clock deadline: hold it until ans2 has sent the positive answer
(a shared event), then wait a short settle for the resolver to cache it.
Both queries traverse the same delegation, so any latency reaching ans2
shifts the positive send and the negative fetch's deadline together and
cancels out; only the settle, kept well under MINIMUM_QUERY_TIMEOUT
(301 ms), has to fit inside the per-query timeout.
Verified that the stabilized test still triggers the
INSIST(namereln == dns_namereln_subdomain) assertion when the resolver
fix is reverted.
Assisted-by: Claude:claude-opus-4-8
(cherry picked from commit 738456d91564526e6f15c3858b4c809cd6749e1e)
(cherry picked from commit 0c20ee4e8e68999ca617434cde65dd3808f57d8c)
Split cname_dname_negcache into per-scenario modules
The DNAME and CNAME scenarios shared a single module, hence a single
module-scoped ns3 (the framework sets servers up per module, not per
test function). test_dname_negcache cached foo.test. DNAME bar.test.;
when test_cname_negcache ran next against the same resolver,
cname.foo.test. was DNAME-mapped to cname.bar.test., so the resolver
never queried ans2 for the self-referential CNAME and that half of the
bug was never exercised. The hardcoded, unanchored "foo.test." watcher
still matched test_dname's leftover SOA, so test_cname passed without
testing anything -- the CNAME assertion had no coverage.
Give each scenario its own module so each gets a fresh server set, and
anchor the watcher to the queried name so a test cannot pass on an
unrelated record.
With the resolver fix reverted, each module now independently triggers
its own assertion:
DNAME query.c INSIST(namereln == dns_namereln_subdomain)
CNAME query.c INSIST(qctx->rdataset == NULL || qctx->qtype == dname)
Assisted-by: Claude:claude-opus-4-8
(cherry picked from commit 3ef0b8d04a1653407cfb9ee88772ae18689b1318)
(cherry picked from commit 887124315f03a006c4dc76e48ae3d0d8aac3c407)
---
.../system/cname_dname_negcache/ans2/ans.py | 148 ++++++++++++++++++
.../system/cname_dname_negcache/common.py | 46 ++++++
.../cname_dname_negcache/ns1/bar.test.db | 5 +
.../cname_dname_negcache/ns1/named.conf.j2 | 24 +++
.../system/cname_dname_negcache/ns1/root.db | 6 +
.../system/cname_dname_negcache/ns1/test.db | 8 +
.../cname_dname_negcache/ns3/named.conf.j2 | 11 ++
.../tests_cname_negcache.py | 16 ++
.../tests_dname_negcache.py | 16 ++
9 files changed, 280 insertions(+)
create mode 100644 bin/tests/system/cname_dname_negcache/ans2/ans.py
create mode 100644 bin/tests/system/cname_dname_negcache/common.py
create mode 100644 bin/tests/system/cname_dname_negcache/ns1/bar.test.db
create mode 100644 bin/tests/system/cname_dname_negcache/ns1/named.conf.j2
create mode 100644 bin/tests/system/cname_dname_negcache/ns1/root.db
create mode 100644 bin/tests/system/cname_dname_negcache/ns1/test.db
create mode 100644 bin/tests/system/cname_dname_negcache/ns3/named.conf.j2
create mode 100644 bin/tests/system/cname_dname_negcache/tests_cname_negcache.py
create mode 100644 bin/tests/system/cname_dname_negcache/tests_dname_negcache.py
diff --git a/bin/tests/system/cname_dname_negcache/ans2/ans.py b/bin/tests/system/cname_dname_negcache/ans2/ans.py
new file mode 100644
index 0000000000..392fe1e088
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/ans2/ans.py
@@ -0,0 +1,148 @@
+"""
+Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+
+SPDX-License-Identifier: MPL-2.0
+
+This Source Code Form is subject to the terms of the Mozilla Public
+License, v. 2.0. If a copy of the MPL was not distributed with this
+file, you can obtain one at https://mozilla.org/MPL/2.0/.
+
+See the COPYRIGHT file distributed with this work for additional
+information regarding copyright ownership.
+"""
+
+from collections.abc import AsyncGenerator
+
+import asyncio
+
+from dns import name, rcode, rdataclass, rdatatype, rrset
+
+from isctest.asyncserver import (
+ AsyncDnsServer,
+ DnsResponseSend,
+ QnameQtypeHandler,
+ QueryContext,
+ StaticResponseHandler,
+)
+
+# The attack relies on the resolver caching the positive CNAME/DNAME answer
+# *before* it processes the negative answer for the same name. The negative
+# answer must therefore be held back until the positive one has been sent, but
+# released again while the negative fetch is still waiting for it.
+#
+# Releasing it at a fixed wall-clock delay (the original approach) is racy: the
+# delay must be larger than the time it takes the resolver to cache the
+# positive answer, yet smaller than the resolver's per-query timeout. Under
+# load -- most notably ThreadSanitizer, which slows down `named` but not this
+# (wall-clock) server -- those bounds can be violated in either direction,
+# making the test either time out (#5946 CI failures) or, worse, silently stop
+# exercising the bug.
+#
+# Instead, gate the negative answer on an event set right after the positive
+# answer is sent. Both queries traverse the same delegation, so any latency in
+# reaching this server shifts the positive send and the negative fetch's
+# deadline together and cancels out; only the small settle below has to fit
+# inside the per-query timeout.
+#
+# _SETTLE must be longer than the few milliseconds the resolver needs to cache
+# the positive answer, and shorter than MINIMUM_QUERY_TIMEOUT (301 ms in
+# lib/dns/resolver.c) so the in-flight negative fetch has not given up yet.
+_SETTLE = 0.1
+
+_dname_positive_sent = asyncio.Event()
+_cname_positive_sent = asyncio.Event()
+
+
+async def _hold_until_positive_cached(positive_sent: asyncio.Event) -> None:
+ await positive_sent.wait()
+ await asyncio.sleep(_SETTLE)
+
+
+def build_rrset(
+ qname: name.Name | str,
+ rtype: rdatatype.RdataType,
+ rdata: str,
+ ttl: int = 300,
+) -> rrset.RRset:
+ return rrset.from_text(qname, ttl, rdataclass.IN, rtype, rdata)
+
+
+class FooTestNsHandler(QnameQtypeHandler, StaticResponseHandler):
+ qnames = ["foo.test."]
+ qtypes = [rdatatype.NS]
+ answer = [build_rrset("foo.test.", rdatatype.NS, "ns.foo.test.")]
+ additional = [build_rrset("ns.foo.test.", rdatatype.A, "10.53.0.2")]
+
+
+class DelayedDnameNegHandler(QnameQtypeHandler, StaticResponseHandler):
+ qnames = ["foo.test."]
+ qtypes = [rdatatype.DNAME]
+ authority = [
+ build_rrset(
+ "foo.test.",
+ rdatatype.SOA,
+ "ns.test. op.ns.test. 2081509183 86400 3600 3600000 300",
+ )
+ ]
+
+ async def get_responses(
+ self, qctx: QueryContext
+ ) -> AsyncGenerator[DnsResponseSend, None]:
+ await _hold_until_positive_cached(_dname_positive_sent)
+ async for response in super().get_responses(qctx):
+ yield response
+
+
+class DnamePosHandler(QnameQtypeHandler, StaticResponseHandler):
+ qnames = ["a.foo.test."]
+ qtypes = [rdatatype.A]
+ answer = [
+ build_rrset("foo.test.", rdatatype.DNAME, "bar.test."),
+ build_rrset("a.foo.test.", rdatatype.CNAME, "a.bar.test."),
+ ]
+
+ async def get_responses(
+ self, qctx: QueryContext
+ ) -> AsyncGenerator[DnsResponseSend, None]:
+ async for response in super().get_responses(qctx):
+ yield response
+ _dname_positive_sent.set()
+
+
+class CnameHandler(QnameQtypeHandler):
+ qnames = ["cname.foo.test."]
+ qtypes = [rdatatype.CNAME, rdatatype.A]
+ answer = [build_rrset("cname.foo.test.", rdatatype.CNAME, "cname.foo.test.")]
+ authority = [
+ build_rrset(
+ "cname.foo.test.",
+ rdatatype.SOA,
+ "ns.test. op.ns.test. 2081509183 86400 3600 3600000 300",
+ )
+ ]
+
+ async def get_responses(
+ self, qctx: QueryContext
+ ) -> AsyncGenerator[DnsResponseSend, None]:
+ if qctx.qtype == rdatatype.CNAME:
+ await _hold_until_positive_cached(_cname_positive_sent)
+ qctx.prepare_new_response(with_zone_data=False)
+ qctx.response.authority.extend(self.authority)
+ yield DnsResponseSend(qctx.response, authoritative=True)
+ else:
+ qctx.prepare_new_response(with_zone_data=False)
+ qctx.response.answer.extend(self.answer)
+ yield DnsResponseSend(qctx.response, authoritative=True)
+ _cname_positive_sent.set()
+
+
+def main() -> None:
+ server = AsyncDnsServer(default_aa=True, default_rcode=rcode.NOERROR)
+ server.install_response_handlers(
+ FooTestNsHandler(), DelayedDnameNegHandler(), DnamePosHandler(), CnameHandler()
+ )
+ server.run()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/bin/tests/system/cname_dname_negcache/common.py b/bin/tests/system/cname_dname_negcache/common.py
new file mode 100644
index 0000000000..397cfdfa3d
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/common.py
@@ -0,0 +1,46 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+from os import environ
+from re import compile as Re
+from re import escape
+from socket import AF_INET, SOCK_DGRAM, socket
+
+import isctest
+
+
+def run_attack(ns, name1, type1, name2, type2):
+ msg1 = isctest.query.create(name1, type1, cd=True)
+ msg2 = isctest.query.create(name2, type2, cd=True)
+ port = int(environ["PORT"])
+
+ with socket(AF_INET, SOCK_DGRAM) as sock:
+ # The order the requests go out doesn't matter. What is important is
+ # that the first query starts recursion before the second query returns
+ # the answer, and the second query returns the answer before the first
+ # query returns the answer. (So, when the NOERROR/NODATA comes back from
+ # the first query, the cache is queried and we get the positive response
+ # cached from the second query attached to the fresp rdataset of the
+ # response of the first query.)
+ # That ordering is enforced by ans2, which holds back the negative
+ # answer to the first query until it has answered the second one (see
+ # ans2/ans.py); the resolver must not crash while reconciling them.
+ sock.sendto(msg1.to_wire(), (ns.ip, port))
+ sock.sendto(msg2.to_wire(), (ns.ip, port))
+
+ # The second query comes back immediately, the resolver caches the DNAME.
+ # The first query comes back shortly after, once ans2 has released the
+ # negative answer, and should not crash the server. Wait for the negative
+ # SOA for this specific name (not just any foo.test. one) so the test cannot
+ # pass on an unrelated record.
+ soa = Re(rf"(?<![\w.]){escape(name1)}.*IN\s+SOA\s+ns\.test\.\s+op\.ns\.test\.")
+ with ns.watch_log_from_start(timeout=15) as watcher:
+ watcher.wait_for_sequence([soa])
diff --git a/bin/tests/system/cname_dname_negcache/ns1/bar.test.db b/bin/tests/system/cname_dname_negcache/ns1/bar.test.db
new file mode 100644
index 0000000000..840b9c3a2c
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/ns1/bar.test.db
@@ -0,0 +1,5 @@
+$TTL 300
+bar.test. IN SOA ns.bar.test. hostmaster.bar.test. 1 600 600 1200 600
+bar.test. NS ns.bar.test.
+ns A 10.53.0.1
+a A 10.0.0.1
diff --git a/bin/tests/system/cname_dname_negcache/ns1/named.conf.j2 b/bin/tests/system/cname_dname_negcache/ns1/named.conf.j2
new file mode 100644
index 0000000000..d72dd1181d
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/ns1/named.conf.j2
@@ -0,0 +1,24 @@
+options {
+ query-source address @ns.ip@;
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { @ns.ip@; };
+ listen-on-v6 { none; };
+ recursion no;
+ dnssec-validation no;
+};
+
+zone "." {
+ type primary;
+ file "root.db";
+};
+
+zone "test." {
+ type primary;
+ file "test.db";
+};
+
+zone "bar.test." {
+ type primary;
+ file "bar.test.db";
+};
diff --git a/bin/tests/system/cname_dname_negcache/ns1/root.db b/bin/tests/system/cname_dname_negcache/ns1/root.db
new file mode 100644
index 0000000000..c456c45b9d
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/ns1/root.db
@@ -0,0 +1,6 @@
+$TTL 300
+. IN SOA ns. hostmaster. 1 600 600 1200 600
+. NS a.root-servers.nil.
+a.root-servers.nil. A 10.53.0.1
+test NS ns.test
+ns.test A 10.53.0.1
diff --git a/bin/tests/system/cname_dname_negcache/ns1/test.db b/bin/tests/system/cname_dname_negcache/ns1/test.db
new file mode 100644
index 0000000000..acb68e00f8
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/ns1/test.db
@@ -0,0 +1,8 @@
+$TTL 300
+test. IN SOA ns.test. hostmaster.test. 1 600 600 1200 600
+test. NS ns.test.
+ns A 10.53.0.1
+bar NS ns.bar
+ns.bar A 10.53.0.1
+foo NS ns.foo
+ns.foo A 10.53.0.2
diff --git a/bin/tests/system/cname_dname_negcache/ns3/named.conf.j2 b/bin/tests/system/cname_dname_negcache/ns3/named.conf.j2
new file mode 100644
index 0000000000..197d72756b
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/ns3/named.conf.j2
@@ -0,0 +1,11 @@
+options {
+ query-source address @ns.ip@;
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { @ns.ip@; };
+ listen-on-v6 { none; };
+ recursion yes;
+ dnssec-validation no;
+};
+
+{% include "_common/root.hint.conf" %}
diff --git a/bin/tests/system/cname_dname_negcache/tests_cname_negcache.py b/bin/tests/system/cname_dname_negcache/tests_cname_negcache.py
new file mode 100644
index 0000000000..a546d29109
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/tests_cname_negcache.py
@@ -0,0 +1,16 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+from cname_dname_negcache.common import run_attack
+
+
+def test_cname_negcache(ns3):
+ run_attack(ns3, "cname.foo.test.", "CNAME", "cname.foo.test.", "A")
diff --git a/bin/tests/system/cname_dname_negcache/tests_dname_negcache.py b/bin/tests/system/cname_dname_negcache/tests_dname_negcache.py
new file mode 100644
index 0000000000..41a80b4e05
--- /dev/null
+++ b/bin/tests/system/cname_dname_negcache/tests_dname_negcache.py
@@ -0,0 +1,16 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+from cname_dname_negcache.common import run_attack
+
+
+def test_dname_negcache(ns3):
+ run_attack(ns3, "foo.test.", "DNAME", "a.foo.test.", "A")
--
2.55.0

View file

@ -0,0 +1,280 @@
From 3138886f3767c0a6b933fd147c5465472209bac6 Mon Sep 17 00:00:00 2001
From: Colin Vidal <colin@isc.org>
Date: Thu, 18 Jun 2026 18:17:05 +0200
Subject: [PATCH] Do not assert in some CNAME/DNAME queries
Fix a `named` crash because of a fail assertion for certains types of
CNAME and DNAME queries:
- If a client queries for a DNAME and A record to the resolver, and the
authoritative server responds positively to the A query but delay the
DNAME response and respond later negatively;
- If a client queries for a CNAME and A record to the resolver, and the
authoritative server responds positively to the A query but delay the
CNAME response and respond later with a self-referential CNAME.
The first scenario consists of sending two queries: `foo.test./DNAME`
and `a.foo.test./A`. The authoritative server delays the answer for
`foo.test./DNAME` but immediately answers the DNAME record for the
second query: `foo.test. DNAME bar.test.`. The resolver caches it,
follows the DNAME, and resolves `a.bar.test./A`. The authoritative
server eventually answers negatively for `foo.test./DNAME`
(NOERROR/NODATA, with only an SOA in the authority section). The
resolver pulls out the previously cached rdataset (because it has a
higher trust level than the received negative answer), and wrongly (this
is the first bug) sets the result to `DNS_R_DNAME` instead of
`ISC_R_SUCCESS`. The code in `ns/query.c` that handles the resolver
result interprets this as "this is a non-DNAME query and we got a DNAME
rdataset, so follow the chain". It goes into the `query_dname()`
function, which asserts that the qname is a subdomain of the owner name
in the rdataset. That assertion fails because the qname (`foo.test.`) is
exactly equal to the owner name of the DNAME (`foo.test.`), rather than
being a subdomain of it. `DNS_R_DNAME` must only be set when the qtype
is something other than DNAME and the resolver has obtained a DNAME that
needs to be followed.
The second scenario consists of sending two queries:
`cname.foo.test./CNAME` and `cname.foo.test./A`. The authoritative
server delays the answer for `cname.foo.test./CNAME` but immediately
answers the CNAME record for the second query: `cname.foo.test. CNAME
cname.foo.test.`. Note that the CNAME is self-referential. The resolver
caches it and sets the result code to `DNS_R_CNAME`. Then `ns/query.c`
interprets this as "this is a non-CNAME query and we got a CNAME
rdataset, so follow the chain" (which is correct in this case; however,
because the CNAME rdataset is self-referential, the resolver responds
with SERVFAIL, which is expected). The authoritative server eventually
answers negatively for `cname.foo.test./CNAME`. The resolver then pulls
out the previously cached CNAME rdataset (obtained from the A answer,
even though it was self-referential, the resolver cached it) and wrongly
sets the result to `DNS_R_CNAME` (this is the second bug). As noted
above, `ns/query.c` interprets this as "this is a non-CNAME query and we
got a CNAME rdataset, so follow the chain". The internals here are
slightly more subtle: it first goes into `query_cname()` and sets the
CNAME rdataset in the message answer section, then restarts the query to
follow the CNAME. The restart retrieves the CNAME rdataset from the
cache directly (without going to the resolver), and this time the query
context result is `ISC_R_SUCCESS` (since it was found) and
`qctx->rdataset` points to the same CNAME again (as it is
self-referential), so it goes directly into the
`query_prepresponse()/query_respond()` flow, which attempts to add the
rdataset to the message answer again. However, this fails because the
rdataset is already in the message, and the assertion which expects that
operation to succeed fails (due to `qctx->rdataset` being set to `NULL`
when ownership of the rdataset was transferred). `DNS_R_CNAME` must only
be set when the qtype is something other than CNAME and the resolver has
obtained a CNAME that needs to be followed.
In both cases, the correct answer from the resolver should have been
`ISC_R_SUCCESS` (instead of respectively `DNS_R_DNAME` and
`DNS_R_CNAME`) becuase the rdataset that has been looked up was found.
(cherry picked from commit 773d46d58c693047a5945c8fe40512edd0ac214e)
(cherry picked from commit c740c37689f234e21a9b0ef760471ef2cf1133f5)
---
lib/dns/resolver.c | 137 ++++++++++++++++++++-------------------------
1 file changed, 60 insertions(+), 77 deletions(-)
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index edc9c207e1..1f8b5058d1 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -692,10 +692,10 @@ fctx_destroy(fetchctx_t *fctx, bool exiting);
static void
send_shutdown_events(dns_resolver_t *res);
static isc_result_t
-ncache_adderesult(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node,
- dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t minttl,
- dns_ttl_t maxttl, bool optout, bool secure,
- dns_rdataset_t *ardataset, isc_result_t *eresultp);
+ncache_adderesult(fetchctx_t *fctx, dns_message_t *message, dns_dbnode_t *node,
+ dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t maxttl,
+ bool optout, bool secure, dns_rdataset_t *ardataset,
+ isc_result_t *eresultp);
static void
validated(isc_task_t *task, isc_event_t *event);
static void
@@ -5563,6 +5563,46 @@ has_000_label(dns_rdataset_t *nsecset) {
return false;
}
+/*
+ * After a (non-error) negative-cache add, 'rdataset' is bound to whatever
+ * rdataset the cache authoritatively holds for the queried name and type.
+ * Map that to the result code the fetch should report:
+ *
+ * - A negative cache entry (the one we just added, or a pre-existing one):
+ * DNS_R_NCACHENXDOMAIN or DNS_R_NCACHENXRRSET, depending on NXDOMAIN vs
+ * NODATA.
+ *
+ * - A positive rdataset that was already cached at higher trust, which
+ * caused our negative entry to be discarded (e.g. a CNAME or DNAME cached
+ * by a concurrent query): ISC_R_SUCCESS, because that cached positive
+ * answer is what gets returned. Note the specific case for CNAME and
+ * DNAME *if* the query type is not the same as the rdataset type. There
+ * is a chain to follow *only* if the query type doesn't ask for the CNAME
+ * or the DNAME.
+ */
+static isc_result_t
+fctx_setresult(fetchctx_t *fctx, dns_rdataset_t *rdataset) {
+ isc_result_t result = ISC_R_SUCCESS;
+
+ if (NEGATIVE(rdataset)) {
+ result = NXDOMAIN(rdataset) ? DNS_R_NCACHENXDOMAIN
+ : DNS_R_NCACHENXRRSET;
+ } else if (result == ISC_R_SUCCESS && rdataset->type != fctx->type) {
+ switch (rdataset->type) {
+ case dns_rdatatype_cname:
+ result = DNS_R_CNAME;
+ break;
+ case dns_rdatatype_dname:
+ result = DNS_R_DNAME;
+ break;
+ default:
+ break;
+ }
+ }
+
+ return result;
+}
+
/*
* The validator has finished.
*/
@@ -5836,8 +5876,7 @@ validated(isc_task_t *task, isc_event_t *event) {
ttl = 0;
}
- result = ncache_adderesult(message, fctx->cache, node, covers,
- now, fctx->res->view->minncachettl,
+ result = ncache_adderesult(fctx, message, node, covers, now,
ttl, vevent->optout, vevent->secure,
ardataset, &eresult);
if (result != ISC_R_SUCCESS) {
@@ -6081,23 +6120,7 @@ answer_response:
*/
INSIST(hevent->rdataset != NULL);
if (dns_rdataset_isassociated(hevent->rdataset)) {
- if (NEGATIVE(hevent->rdataset)) {
- INSIST(eresult == DNS_R_NCACHENXDOMAIN ||
- eresult == DNS_R_NCACHENXRRSET);
- } else if (eresult == ISC_R_SUCCESS &&
- hevent->rdataset->type != fctx->type)
- {
- switch (hevent->rdataset->type) {
- case dns_rdatatype_cname:
- eresult = DNS_R_CNAME;
- break;
- case dns_rdatatype_dname:
- eresult = DNS_R_DNAME;
- break;
- default:
- break;
- }
- }
+ eresult = fctx_setresult(fctx, hevent->rdataset);
}
hevent->result = eresult;
@@ -6747,24 +6770,7 @@ cache_name(fetchctx_t *fctx, dns_name_t *name, dns_message_t *message,
* event->result.
*/
if (dns_rdataset_isassociated(event->rdataset)) {
- if (NEGATIVE(event->rdataset)) {
- INSIST(eresult ==
- DNS_R_NCACHENXDOMAIN ||
- eresult == DNS_R_NCACHENXRRSET);
- } else if (eresult == ISC_R_SUCCESS &&
- event->rdataset->type != fctx->type)
- {
- switch (event->rdataset->type) {
- case dns_rdatatype_cname:
- eresult = DNS_R_CNAME;
- break;
- case dns_rdatatype_dname:
- eresult = DNS_R_DNAME;
- break;
- default:
- break;
- }
- }
+ eresult = fctx_setresult(fctx, event->rdataset);
}
event->result = eresult;
if (adbp != NULL && *adbp != NULL) {
@@ -6833,12 +6839,14 @@ cache_message(fetchctx_t *fctx, dns_message_t *message,
* eresult.
*/
static isc_result_t
-ncache_adderesult(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node,
- dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t minttl,
- dns_ttl_t maxttl, bool optout, bool secure,
- dns_rdataset_t *ardataset, isc_result_t *eresultp) {
+ncache_adderesult(fetchctx_t *fctx, dns_message_t *message, dns_dbnode_t *node,
+ dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t maxttl,
+ bool optout, bool secure, dns_rdataset_t *ardataset,
+ isc_result_t *eresultp) {
isc_result_t result;
dns_rdataset_t rdataset;
+ dns_db_t *cache = fctx->cache;
+ dns_ttl_t minttl = fctx->res->view->minncachettl;
if (ardataset == NULL) {
dns_rdataset_init(&rdataset);
@@ -6854,37 +6862,13 @@ ncache_adderesult(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node,
}
if (result == DNS_R_UNCHANGED || result == ISC_R_SUCCESS) {
/*
- * If the cache now contains a negative entry and we
- * care about whether it is DNS_R_NCACHENXDOMAIN or
- * DNS_R_NCACHENXRRSET then extract it.
+ * The cache settled successfully (DNS_R_UNCHANGED means our
+ * negative entry was discarded in favour of existing
+ * higher-trust data). Either way 'ardataset' is now bound to
+ * the rdataset the cache holds for this name and type; derive
+ * the result code from it.
*/
- if (NEGATIVE(ardataset)) {
- /*
- * The cache data is a negative cache entry.
- */
- if (NXDOMAIN(ardataset)) {
- *eresultp = DNS_R_NCACHENXDOMAIN;
- } else {
- *eresultp = DNS_R_NCACHENXRRSET;
- }
- } else {
- /*
- * The attempt to add a negative cache entry
- * was rejected. Set *eresultp to reflect
- * the type of the dataset being returned.
- */
- switch (ardataset->type) {
- case dns_rdatatype_cname:
- *eresultp = DNS_R_CNAME;
- break;
- case dns_rdatatype_dname:
- *eresultp = DNS_R_DNAME;
- break;
- default:
- *eresultp = ISC_R_SUCCESS;
- break;
- }
- }
+ *eresultp = fctx_setresult(fctx, ardataset);
result = ISC_R_SUCCESS;
}
if (ardataset == &rdataset && dns_rdataset_isassociated(ardataset)) {
@@ -7029,8 +7013,7 @@ ncache_message(fetchctx_t *fctx, dns_message_t *message,
ttl = 0;
}
- result = ncache_adderesult(message, fctx->cache, node, covers, now,
- fctx->res->view->minncachettl, ttl, false,
+ result = ncache_adderesult(fctx, message, node, covers, now, ttl, false,
false, ardataset, &eresult);
if (result != ISC_R_SUCCESS) {
goto unlock;
--
2.55.0

View file

@ -0,0 +1,416 @@
From 89e950d215e9922e5af6e3c69b9d6a8750346bb6 Mon Sep 17 00:00:00 2001
From: Alessio Podda <alessio@isc.org>
Date: Fri, 12 Jun 2026 11:16:01 +0200
Subject: [PATCH] Reproducer for #5985 addnoqname mismatch
LLM generated.
(cherry picked from commit 5f4de929b3e4749b6e32c51660be11c47c2514e6)
(cherry picked from commit 0cf010c153518f1f9831e201891ecba8d8ba65e1)
Update reproducer #5985
Update the llm generated reproducer:
- Move server.py into ans/ans1.py
- Remove unncessary named.conf configuration options
- Add comments describing the steps
- Rename system test
(cherry picked from commit fd539807829dd7d2eb76c8b503083f5d84fec6f0)
(cherry picked from commit 6c0e599ea85c0c53a4af09742e64e193da089bb4)
---
.../dnssec_findnoqname_mismatch/ans1/ans.py | 207 ++++++++++++++++++
.../ns2/named.conf.j2 | 33 +++
.../tests_findnoqname_mismatch.py | 126 +++++++++++
3 files changed, 366 insertions(+)
create mode 100644 bin/tests/system/dnssec_findnoqname_mismatch/ans1/ans.py
create mode 100644 bin/tests/system/dnssec_findnoqname_mismatch/ns2/named.conf.j2
create mode 100644 bin/tests/system/dnssec_findnoqname_mismatch/tests_findnoqname_mismatch.py
diff --git a/bin/tests/system/dnssec_findnoqname_mismatch/ans1/ans.py b/bin/tests/system/dnssec_findnoqname_mismatch/ans1/ans.py
new file mode 100644
index 0000000000..b36fc831c8
--- /dev/null
+++ b/bin/tests/system/dnssec_findnoqname_mismatch/ans1/ans.py
@@ -0,0 +1,207 @@
+#!/usr/bin/python3
+
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+
+from collections.abc import AsyncGenerator
+from dataclasses import dataclass
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+
+import base64
+import json
+
+from cryptography.hazmat.primitives import serialization
+
+import dns.dnssec
+import dns.flags
+import dns.message
+import dns.name
+import dns.rdata
+import dns.rdataclass
+import dns.rcode
+import dns.rdatatype
+import dns.rrset
+
+from isctest.asyncserver import (
+ AsyncDnsServer,
+ DnsResponseSend,
+ QueryContext,
+ ResponseHandler,
+)
+
+TTL = 300
+ZONE = "f217.test."
+CHILD = f"evil.{ZONE}"
+ATTACK = f"www.{CHILD}"
+NSEC_OWNER = f"00000000.{CHILD}"
+NSEC_NEXT = f"zzz.{CHILD}"
+FORGED_A = "192.0.2.217"
+
+
+@dataclass(frozen=True)
+class Key:
+ zone: dns.name.Name
+ private_key: object
+ dnskey: dns.rdata.Rdata
+
+
+def name(text: str) -> dns.name.Name:
+ return dns.name.from_text(text)
+
+
+def load_key() -> Key:
+ path = Path(__file__).resolve().parent / "keys.json"
+ with path.open(encoding="utf-8") as keys_file:
+ raw_key = json.load(keys_file)[ZONE]
+
+ private_key = serialization.load_pem_private_key(
+ raw_key["private_pem"].encode("ascii"),
+ password=None,
+ )
+ dnskey = dns.rdata.from_text(
+ dns.rdataclass.IN, dns.rdatatype.DNSKEY, raw_key["dnskey"]
+ )
+ return Key(name(ZONE), private_key, dnskey)
+
+
+def rrset(owner: str, rdtype: dns.rdatatype.RdataType, *rdatas: str) -> dns.rrset.RRset:
+ return dns.rrset.from_text(owner, TTL, dns.rdataclass.IN, rdtype, *rdatas)
+
+
+def rrset_from_rdata(owner: str, rdata: dns.rdata.Rdata) -> dns.rrset.RRset:
+ return dns.rrset.from_rdata(name(owner), TTL, rdata)
+
+
+def add_signed(
+ section: list[dns.rrset.RRset], covered: dns.rrset.RRset, signer: Key
+) -> None:
+ rrsig = dns.dnssec.sign(
+ covered,
+ signer.private_key,
+ signer.zone,
+ signer.dnskey,
+ lifetime=86400,
+ verify=True,
+ )
+ section.append(covered)
+ section.append(dns.rrset.from_rdata(covered.name, covered.ttl, rrsig))
+
+
+def soa_rrset(zone: str) -> dns.rrset.RRset:
+ return rrset(
+ zone,
+ dns.rdatatype.SOA,
+ f"ns.{ZONE} hostmaster.{ZONE} 1 7200 3600 1209600 300",
+ )
+
+
+def garbage_rrsig(
+ owner: str, covered: dns.rdatatype.RdataType, labels: int, signer: str
+) -> dns.rrset.RRset:
+ now = datetime.now(timezone.utc)
+ inception = (now - timedelta(hours=1)).strftime("%Y%m%d%H%M%S")
+ expiration = (now + timedelta(days=1)).strftime("%Y%m%d%H%M%S")
+ signature = base64.b64encode(bytes(64)).decode("ascii")
+ text = (
+ f"{dns.rdatatype.to_text(covered)} 13 {labels} {TTL} "
+ f"{expiration} {inception} 12345 {signer} {signature}"
+ )
+ rdata = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.RRSIG, text)
+ return dns.rrset.from_rdata(name(owner), TTL, rdata)
+
+
+def add_ds_denial(response: dns.message.Message, key: Key) -> None:
+ add_signed(response.authority, soa_rrset(ZONE), key)
+ nsec = rrset(CHILD, dns.rdatatype.NSEC, f"ns.{ZONE} NS RRSIG NSEC")
+ add_signed(response.authority, nsec, key)
+
+
+def add_attack_answer(response: dns.message.Message) -> None:
+ """
+ Crafted authoritative response to <q>.evil.f217.hack./A
+
+ ;; ANSWER
+ <q>.evil.f217.hack. 300 IN A 192.0.2.217
+ <q>.evil.f217.hack. 300 IN RRSIG A 13 1 300 <exp> <inc> 12345 evil.f217.hack. <base64 of 64×0x00>
+ ^^^ Labels = 1, qname has 4 labels, wildcard heuristic fires
+
+ ;; AUTHORITY (single owner, three rdatasets in this wire order)
+ 00000000.evil.f217.hack. 300 IN NSEC zzz.evil.f217.hack. A RRSIG NSEC
+ 00000000.evil.f217.hack. 300 IN RRSIG NSEC 13 4 300 <exp> <inc> 12345 evil.f217.hack. <base64 of 64×0x00>
+ 00000000.evil.f217.hack. 300 IN NSEC3 1 0 0 - VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV A RRSIG
+ """
+ # A + RRSIG
+ response.answer.append(rrset(ATTACK, dns.rdatatype.A, FORGED_A))
+ response.answer.append(garbage_rrsig(ATTACK, dns.rdatatype.A, 1, CHILD))
+ # NSEC
+ nsec = rrset(
+ NSEC_OWNER,
+ dns.rdatatype.NSEC,
+ f"{NSEC_NEXT} A RRSIG NSEC",
+ )
+ response.authority.append(nsec)
+ # RRSIG(NSEC)
+ response.authority.append(
+ garbage_rrsig(
+ NSEC_OWNER,
+ dns.rdatatype.NSEC,
+ len(name(NSEC_OWNER).labels) - 1,
+ CHILD,
+ )
+ )
+ # NSEC3
+ nsec3 = rrset(
+ NSEC_OWNER,
+ dns.rdatatype.NSEC3,
+ "1 0 0 - VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV A RRSIG",
+ )
+ response.authority.append(nsec3)
+
+
+class RuntimeCheckHandler(ResponseHandler):
+ def __init__(self, key: Key) -> None:
+ self.key = key
+ self.zone = name(ZONE)
+ self.child = name(CHILD)
+ self.attack = name(ATTACK)
+
+ def match(self, qctx: QueryContext) -> bool:
+ return qctx.qname.is_subdomain(self.zone)
+
+ async def get_responses(
+ self, qctx: QueryContext
+ ) -> AsyncGenerator[DnsResponseSend, None]:
+ qctx.prepare_new_response(with_zone_data=False)
+ qctx.response.flags |= dns.flags.AA
+ qctx.response.set_rcode(dns.rcode.NOERROR)
+
+ if qctx.qname == self.zone and qctx.qtype == dns.rdatatype.DNSKEY:
+ add_signed(
+ qctx.response.answer,
+ rrset_from_rdata(ZONE, self.key.dnskey),
+ self.key,
+ )
+ elif qctx.qname == self.zone and qctx.qtype == dns.rdatatype.SOA:
+ add_signed(qctx.response.answer, soa_rrset(ZONE), self.key)
+ elif qctx.qname == self.child and qctx.qtype == dns.rdatatype.DS:
+ add_ds_denial(qctx.response, self.key)
+ elif qctx.qname == self.child and qctx.qtype == dns.rdatatype.DNSKEY:
+ qctx.response.authority.append(soa_rrset(CHILD))
+ elif qctx.qname == self.attack and qctx.qtype == dns.rdatatype.A:
+ add_attack_answer(qctx.response)
+ else:
+ add_signed(qctx.response.authority, soa_rrset(ZONE), self.key)
+
+ yield DnsResponseSend(qctx.response, authoritative=True)
+
+
+def main() -> None:
+ server = AsyncDnsServer(default_aa=True)
+ server.install_response_handlers(RuntimeCheckHandler(load_key()))
+ server.run()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/bin/tests/system/dnssec_findnoqname_mismatch/ns2/named.conf.j2 b/bin/tests/system/dnssec_findnoqname_mismatch/ns2/named.conf.j2
new file mode 100644
index 0000000000..f4fbd8a617
--- /dev/null
+++ b/bin/tests/system/dnssec_findnoqname_mismatch/ns2/named.conf.j2
@@ -0,0 +1,33 @@
+// validating resolver
+
+options {
+ query-source address 10.53.0.2;
+ notify-source 10.53.0.2;
+ transfer-source 10.53.0.2;
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { 10.53.0.2; };
+ listen-on-v6 { none; };
+ recursion yes;
+ dnssec-validation yes;
+};
+
+controls {
+ inet 10.53.0.2 port @CONTROLPORT@ allow { any; } keys { rndc_key; };
+};
+
+include "../../_common/rndc.key";
+
+zone "." {
+ type hint;
+ file "../../_common/root.hint";
+};
+
+zone "f217.test" {
+ type static-stub;
+ server-addresses { 10.53.0.1; };
+};
+
+trust-anchors {
+ f217.test. static-key 257 3 13 "@ZONE_DNSKEY@";
+};
diff --git a/bin/tests/system/dnssec_findnoqname_mismatch/tests_findnoqname_mismatch.py b/bin/tests/system/dnssec_findnoqname_mismatch/tests_findnoqname_mismatch.py
new file mode 100644
index 0000000000..f3e332a360
--- /dev/null
+++ b/bin/tests/system/dnssec_findnoqname_mismatch/tests_findnoqname_mismatch.py
@@ -0,0 +1,126 @@
+#!/usr/bin/python3
+
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+
+from pathlib import Path
+
+import json
+
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import ec
+
+import dns.dnssec
+import dns.name
+import dns.rdataclass
+import dns.rdatatype
+import pytest
+
+import isctest
+import isctest.mark
+
+ZONE = "f217.test."
+CHILD = f"evil.{ZONE}"
+ATTACK = f"www.{CHILD}"
+NSEC_OWNER = f"00000000.{CHILD}"
+FORGED_A = "192.0.2.217"
+AUTH = "10.53.0.1"
+RESOLVER = "10.53.0.2"
+
+pytestmark = [
+ isctest.mark.with_ecdsa_deterministic,
+ pytest.mark.extra_artifacts(
+ [
+ "ans1/ans.run",
+ "ans1/keys.json",
+ ]
+ ),
+]
+
+
+def _make_key():
+ private_key = ec.generate_private_key(ec.SECP256R1())
+ dnskey = dns.dnssec.make_dnskey(
+ private_key.public_key(),
+ algorithm="ECDSAP256SHA256",
+ flags=257,
+ )
+ private_pem = private_key.private_bytes(
+ encoding=serialization.Encoding.PEM,
+ format=serialization.PrivateFormat.PKCS8,
+ encryption_algorithm=serialization.NoEncryption(),
+ ).decode("ascii")
+ return {
+ "private_pem": private_pem,
+ "dnskey": dnskey.to_text(),
+ }
+
+
+def bootstrap():
+ keys = {ZONE: _make_key()}
+ Path("ans1/keys.json").write_text(json.dumps(keys, indent=2), encoding="ascii")
+ zone_dnskey = "".join(keys[ZONE]["dnskey"].split()[3:])
+ return {"ZONE_DNSKEY": zone_dnskey}
+
+
+def _query(server, qname, qtype):
+ query = isctest.query.create(qname, qtype)
+ return isctest.query.tcp(query, server, attempts=1, timeout=5)
+
+
+def _rrset(response, section, owner, rdtype, covers=None):
+ if covers is None:
+ return response.get_rrset(
+ section, dns.name.from_text(owner), dns.rdataclass.IN, rdtype
+ )
+ return response.get_rrset(
+ section,
+ dns.name.from_text(owner),
+ dns.rdataclass.IN,
+ rdtype,
+ covers=covers,
+ )
+
+
+def _has_a(response, section, owner, address):
+ rrset = _rrset(response, section, owner, dns.rdatatype.A)
+ return rrset is not None and any(rdata.address == address for rdata in rrset)
+
+
+def _check_rrsig(response, section, owner, rdtype, signer, labels=None):
+ rrsig = _rrset(response, section, owner, dns.rdatatype.RRSIG, covers=rdtype)
+ assert rrsig is not None, response.to_text()
+ assert rrsig[0].signer == dns.name.from_text(signer), response.to_text()
+ if labels is not None:
+ assert rrsig[0].labels == labels, response.to_text()
+
+
+def test_malicious_findnoqname_addnoqname_mismatch():
+ response = _query(AUTH, ATTACK, "A")
+ isctest.check.noerror(response)
+ assert _has_a(response, response.answer, ATTACK, FORGED_A), response.to_text()
+ _check_rrsig(response, response.answer, ATTACK, dns.rdatatype.A, CHILD, labels=1)
+
+ # Has NSEC
+ assert _rrset(response, response.authority, NSEC_OWNER, dns.rdatatype.NSEC)
+ _check_rrsig(response, response.authority, NSEC_OWNER, dns.rdatatype.NSEC, CHILD)
+ # Has NSEC3
+ assert _rrset(response, response.authority, NSEC_OWNER, dns.rdatatype.NSEC3)
+ assert (
+ _rrset(
+ response,
+ response.authority,
+ NSEC_OWNER,
+ dns.rdatatype.RRSIG,
+ covers=dns.rdatatype.NSEC3,
+ )
+ is None
+ )
+
+
+def test_resolver_findnoqname_addnoqname_mismatch():
+ # Send one trigger query
+ _query(RESOLVER, ATTACK, "A")
+ response = _query(RESOLVER, ZONE, "SOA")
+ isctest.check.noerror(response)
--
2.55.0

View file

@ -0,0 +1,158 @@
From 895cac04332d85489ddf881b28e18e9956f6e348 Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Wed, 13 May 2026 20:45:57 -0700
Subject: [PATCH] dns_rdataset_addnoqname() could find unsigned NSEC/NSEC3
The dns_rdatalist addnoqname() implementation searches for the first
NSEC or NSEC3 record in a message, then for the first RRSIG covering
that type in the same message. Previously, if no RRSIG for the type was
found, the function accepted the unsigned record. Now, it will instead
continue searching until an NSEC or NSEC3 that does have a matching
signature is found.
When this function is called from validated() in resolver.c, a
non-success return code is now treated as an error instead of triggering
an assertion failure.
Fixes: isc-projects/bind9#5985
(cherry picked from commit 57cba571ee31311e54d8a11cb38094d439f04e09)
(cherry picked from commit 48f5aa5fb3746d6194edcc57e8792a8b3cc3b454)
---
lib/dns/rbtdb.c | 10 +++++++---
lib/dns/rdatalist.c | 33 ++++++++++++++++-----------------
lib/dns/resolver.c | 4 +++-
lib/ns/query.c | 3 +--
4 files changed, 27 insertions(+), 23 deletions(-)
diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 0b8547950f..c922df557b 100644
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -6946,7 +6946,7 @@ delegating_type(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node,
static isc_result_t
addnoqname(dns_rbtdb_t *rbtdb, rdatasetheader_t *newheader,
uint32_t maxrrperset, dns_rdataset_t *rdataset) {
- struct noqname *noqname;
+ struct noqname *noqname = NULL;
isc_mem_t *mctx = rbtdb->common.mctx;
dns_name_t name;
dns_rdataset_t neg, negsig;
@@ -6958,7 +6958,9 @@ addnoqname(dns_rbtdb_t *rbtdb, rdatasetheader_t *newheader,
dns_rdataset_init(&negsig);
result = dns_rdataset_getnoqname(rdataset, &name, &neg, &negsig);
- RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ if (result != ISC_R_SUCCESS) {
+ goto cleanup;
+ }
noqname = isc_mem_get(mctx, sizeof(*noqname));
dns_name_init(&noqname->name, NULL);
@@ -6984,7 +6986,9 @@ addnoqname(dns_rbtdb_t *rbtdb, rdatasetheader_t *newheader,
cleanup:
dns_rdataset_disassociate(&neg);
dns_rdataset_disassociate(&negsig);
- free_noqname(mctx, &noqname);
+ if (noqname != NULL) {
+ free_noqname(mctx, &noqname);
+ }
return result;
}
diff --git a/lib/dns/rdatalist.c b/lib/dns/rdatalist.c
index 98036f9cb3..2cca8d64be 100644
--- a/lib/dns/rdatalist.c
+++ b/lib/dns/rdatalist.c
@@ -192,6 +192,7 @@ isc__rdatalist_addnoqname(dns_rdataset_t *rdataset, const dns_name_t *name) {
dns_rdataset_t *neg = NULL;
dns_rdataset_t *negsig = NULL;
dns_rdataset_t *rdset;
+ dns_rdataset_t *sigset;
dns_ttl_t ttl;
REQUIRE(rdataset != NULL);
@@ -199,30 +200,27 @@ isc__rdatalist_addnoqname(dns_rdataset_t *rdataset, const dns_name_t *name) {
for (rdset = ISC_LIST_HEAD(name->list); rdset != NULL;
rdset = ISC_LIST_NEXT(rdset, link))
{
- if (rdset->rdclass != rdataset->rdclass) {
- continue;
- }
- if (rdset->type == dns_rdatatype_nsec ||
- rdset->type == dns_rdatatype_nsec3)
+ if (rdset->rdclass != rdataset->rdclass ||
+ (rdset->type != dns_rdatatype_nsec &&
+ rdset->type != dns_rdatatype_nsec3))
{
- neg = rdset;
+ continue;
}
- }
- if (neg == NULL) {
- return ISC_R_NOTFOUND;
- }
- for (rdset = ISC_LIST_HEAD(name->list); rdset != NULL;
- rdset = ISC_LIST_NEXT(rdset, link))
- {
- if (rdset->type == dns_rdatatype_rrsig &&
- rdset->covers == neg->type)
+ for (sigset = ISC_LIST_HEAD(name->list); sigset != NULL;
+ sigset = ISC_LIST_NEXT(sigset, link))
{
- negsig = rdset;
+ if (sigset->type == dns_rdatatype_rrsig &&
+ sigset->covers == rdset->type)
+ {
+ neg = rdset;
+ negsig = sigset;
+ break;
+ }
}
}
- if (negsig == NULL) {
+ if (neg == NULL || negsig == NULL) {
return ISC_R_NOTFOUND;
}
/*
@@ -238,6 +236,7 @@ isc__rdatalist_addnoqname(dns_rdataset_t *rdataset, const dns_name_t *name) {
rdataset->ttl = neg->ttl = negsig->ttl = ttl;
rdataset->attributes |= DNS_RDATASETATTR_NOQNAME;
rdataset->private6 = name;
+
return ISC_R_SUCCESS;
}
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 1f8b5058d1..059ce53a9e 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -5893,7 +5893,9 @@ validated(isc_task_t *task, isc_event_t *event) {
result = dns_rdataset_addnoqname(
vevent->rdataset,
vevent->proofs[DNS_VALIDATOR_NOQNAMEPROOF]);
- RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ if (result != ISC_R_SUCCESS) {
+ goto noanswer_response;
+ }
INSIST(vevent->sigrdataset != NULL);
vevent->sigrdataset->ttl = vevent->rdataset->ttl;
if (vevent->proofs[DNS_VALIDATOR_CLOSESTENCLOSER] != NULL) {
diff --git a/lib/ns/query.c b/lib/ns/query.c
index 3bd7daf79c..2a2ba1daba 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -7953,8 +7953,7 @@ query_addnoqnameproof(query_ctx_t *qctx) {
goto cleanup;
}
- result = dns_rdataset_getnoqname(qctx->noqname, fname, neg, negsig);
- RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ CHECK(dns_rdataset_getnoqname(qctx->noqname, fname, neg, negsig));
query_addrrset(qctx, &fname, &neg, &negsig, dbuf,
DNS_SECTION_AUTHORITY);
--
2.55.0

View file

@ -0,0 +1,445 @@
From eaa35628f4a201049295a8944f4d28e8a1013199 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ayd=C4=B1n=20Mercan?= <aydin@isc.org>
Date: Wed, 6 May 2026 16:54:57 +0300
Subject: [PATCH] Add system test for out-of-zone nsec dnssec bypass
A malicious zone with out-of-zone NSEC entries can get a DNSSEC
validating resolver's cache to cover the victim zone for non-existence
and prevent nameserver queries without DNSSEC failure.
Test for this case with an `evil.test` zone that tries to cover the
`victim.test` zone.
(cherry picked from commit 654f9773c0af59965c343bdfeb096b3dffe9dd53)
(cherry picked from commit c969ad2c17b43dd999e358bfeb280d3df6fab822)
---
.../system/dnssec_bypass/ns1/named.conf.j2 | 31 ++++
bin/tests/system/dnssec_bypass/ns1/root.db | 19 +++
bin/tests/system/dnssec_bypass/ns1/test.db | 23 +++
.../system/dnssec_bypass/ns2/named.conf.j2 | 26 +++
bin/tests/system/dnssec_bypass/ns2/victim.db | 18 +++
bin/tests/system/dnssec_bypass/ns3/evil.db | 23 +++
.../system/dnssec_bypass/ns3/named.conf.j2 | 26 +++
.../system/dnssec_bypass/ns4/named.conf.j2 | 35 ++++
.../system/dnssec_bypass/tests_bypass.py | 152 ++++++++++++++++++
9 files changed, 353 insertions(+)
create mode 100644 bin/tests/system/dnssec_bypass/ns1/named.conf.j2
create mode 100644 bin/tests/system/dnssec_bypass/ns1/root.db
create mode 100644 bin/tests/system/dnssec_bypass/ns1/test.db
create mode 100644 bin/tests/system/dnssec_bypass/ns2/named.conf.j2
create mode 100644 bin/tests/system/dnssec_bypass/ns2/victim.db
create mode 100644 bin/tests/system/dnssec_bypass/ns3/evil.db
create mode 100644 bin/tests/system/dnssec_bypass/ns3/named.conf.j2
create mode 100644 bin/tests/system/dnssec_bypass/ns4/named.conf.j2
create mode 100644 bin/tests/system/dnssec_bypass/tests_bypass.py
diff --git a/bin/tests/system/dnssec_bypass/ns1/named.conf.j2 b/bin/tests/system/dnssec_bypass/ns1/named.conf.j2
new file mode 100644
index 0000000000..59ced1831a
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns1/named.conf.j2
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+options {
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { 10.53.0.1; };
+ listen-on-v6 { none; };
+ recursion no;
+ dnssec-validation no;
+};
+
+zone "test." {
+ type primary;
+ file "test.db.signed";
+};
+
+zone "." {
+ type primary;
+ file "root.db.signed";
+};
diff --git a/bin/tests/system/dnssec_bypass/ns1/root.db b/bin/tests/system/dnssec_bypass/ns1/root.db
new file mode 100644
index 0000000000..8d98a0456c
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns1/root.db
@@ -0,0 +1,19 @@
+; Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+;
+; SPDX-License-Identifier: MPL-2.0
+;
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0. If a copy of the MPL was not distributed with this
+; file, you can obtain one at https://mozilla.org/MPL/2.0/.
+;
+; See the COPYRIGHT file distributed with this work for additional
+; information regarding copyright ownership.
+
+$TTL 3600
+. IN SOA a.nil. a.nil. 1 3600 600 86400 300
+. IN NS a.root-servers.nil.
+
+a.root-servers.nil. IN A 10.53.0.1
+
+test. IN NS ns1.test.
+ns1.test. IN A 10.53.0.1
diff --git a/bin/tests/system/dnssec_bypass/ns1/test.db b/bin/tests/system/dnssec_bypass/ns1/test.db
new file mode 100644
index 0000000000..6efcd95e42
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns1/test.db
@@ -0,0 +1,23 @@
+; Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+;
+; SPDX-License-Identifier: MPL-2.0
+;
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0. If a copy of the MPL was not distributed with this
+; file, you can obtain one at https://mozilla.org/MPL/2.0/.
+;
+; See the COPYRIGHT file distributed with this work for additional
+; information regarding copyright ownership.
+
+$ORIGIN test.
+$TTL 3600
+
+@ IN SOA a a 1 3600 600 86400 300
+ IN NS ns1.test.
+ns1 IN A 10.53.0.1
+
+evil IN NS ns1.evil
+ns1.evil IN A 10.53.0.3
+
+victim IN NS ns1.victim
+ns1.victim IN A 10.53.0.2
diff --git a/bin/tests/system/dnssec_bypass/ns2/named.conf.j2 b/bin/tests/system/dnssec_bypass/ns2/named.conf.j2
new file mode 100644
index 0000000000..e81cee7cac
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns2/named.conf.j2
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+options {
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { 10.53.0.2; };
+ listen-on-v6 { none; };
+ recursion no;
+ dnssec-validation no;
+};
+
+zone "victim.test." {
+ type primary;
+ file "victim.db.signed";
+};
diff --git a/bin/tests/system/dnssec_bypass/ns2/victim.db b/bin/tests/system/dnssec_bypass/ns2/victim.db
new file mode 100644
index 0000000000..edcc234322
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns2/victim.db
@@ -0,0 +1,18 @@
+; Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+;
+; SPDX-License-Identifier: MPL-2.0
+;
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0. If a copy of the MPL was not distributed with this
+; file, you can obtain one at https://mozilla.org/MPL/2.0/.
+;
+; See the COPYRIGHT file distributed with this work for additional
+; information regarding copyright ownership.
+
+$ORIGIN victim.test.
+$TTL 3600
+
+@ IN SOA ns1 hostmaster 1 3600 600 86400 2147483647
+ IN NS ns1
+
+ns1 IN A 10.53.0.2
diff --git a/bin/tests/system/dnssec_bypass/ns3/evil.db b/bin/tests/system/dnssec_bypass/ns3/evil.db
new file mode 100644
index 0000000000..618f9d3e85
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns3/evil.db
@@ -0,0 +1,23 @@
+; Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+;
+; SPDX-License-Identifier: MPL-2.0
+;
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0. If a copy of the MPL was not distributed with this
+; file, you can obtain one at https://mozilla.org/MPL/2.0/.
+;
+; See the COPYRIGHT file distributed with this work for additional
+; information regarding copyright ownership.
+
+$ORIGIN evil.test.
+$TTL 300
+
+@ IN SOA ns1 hostmaster 1 3600 600 86400 300
+ IN NS ns1
+; Try to poison the victim zone in a resolver cache.
+; If admitted, the aggressive NSEC cache will accept a range such as
+; [evil.test, b.victim.test) and will cause the victim nameserver to
+; be never queried.
+ IN NSEC b.victim.test. NS SOA RRSIG NSEC DNSKEY
+
+ns1 IN A 10.53.0.3
diff --git a/bin/tests/system/dnssec_bypass/ns3/named.conf.j2 b/bin/tests/system/dnssec_bypass/ns3/named.conf.j2
new file mode 100644
index 0000000000..17d3e18e4e
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns3/named.conf.j2
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+options {
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { 10.53.0.3; };
+ listen-on-v6 { none; };
+ recursion no;
+ dnssec-validation no;
+};
+
+zone "evil.test." {
+ type primary;
+ file "evil.db.signed";
+};
diff --git a/bin/tests/system/dnssec_bypass/ns4/named.conf.j2 b/bin/tests/system/dnssec_bypass/ns4/named.conf.j2
new file mode 100644
index 0000000000..039695d9b7
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/ns4/named.conf.j2
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+options {
+ query-source address 10.53.0.4;
+ notify-source 10.53.0.4;
+ transfer-source 10.53.0.4;
+ port @PORT@;
+ pid-file "named.pid";
+ listen-on { 10.53.0.4; };
+ listen-on-v6 { none; };
+ allow-transfer { any; };
+ recursion yes;
+ dnssec-validation yes;
+ synth-from-dnssec yes;
+};
+
+trust-anchors {
+ @root.domain@ @root.type@ @root.contents@;
+};
+
+zone "." {
+ type hint;
+ file "../../_common/root.hint";
+};
diff --git a/bin/tests/system/dnssec_bypass/tests_bypass.py b/bin/tests/system/dnssec_bypass/tests_bypass.py
new file mode 100644
index 0000000000..c41bb7e016
--- /dev/null
+++ b/bin/tests/system/dnssec_bypass/tests_bypass.py
@@ -0,0 +1,152 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+from datetime import datetime, timedelta, timezone
+
+import shutil
+
+from cryptography.hazmat.primitives.asymmetric import ec
+
+import dns.dnssec
+import dns.name
+import dns.rdataclass
+import dns.rdataset
+import dns.rdatatype
+import dns.rrset
+import dns.zone
+
+from isctest.run import EnvCmd
+
+import isctest
+
+TTL = 3600
+
+
+def bootstrap():
+ keygen = EnvCmd("KEYGEN", "-q -a ECDSA256")
+ signer = EnvCmd("SIGNER", "-S -g -O full")
+
+ def sign_regular_zone(ns: str, zone: str, database: str) -> isctest.kasp.Key:
+ isctest.log.info(f"{zone}: generate keys")
+ keygen(zone, cwd=ns).out.strip()
+ ksk = keygen(f"-f KSK {zone}", cwd=ns).out.strip()
+
+ isctest.log.info(f"{zone}: sign zone")
+ signer(f"-o {zone} {database}", cwd=ns)
+
+ if ns != "ns1":
+ shutil.copy(f"{ns}/dsset-{zone}", f"ns1/dsset-{zone}")
+ shutil.copy(f"{ns}/{ksk}.key", f"ns1/{ksk}.key")
+
+ return isctest.kasp.Key(ksk, keydir=ns)
+
+ # dnssec-signzone and `dns.dnssec.sign_zone` correctly disregard the invalid
+ # NSEC entries when signing the zone. However, for this test we actualy *want*
+ # to serve invalid yet signed zones. To accomplish this we sign the zone and then
+ # replace the correct entries with the faulty ones accompanied by its RRSIG.
+ #
+ # TODO(aydin): move this to `isctest` to sign broken zones
+ def sign_rogue_zone(ns: str, zone: str, database: str) -> None:
+ # Read zone.
+ origin = dns.name.from_text(zone)
+ data = dns.zone.from_file(f"{ns}/{database}", origin=origin, relativize=False)
+
+ # Get key for signing.
+ isctest.log.info(f"{zone}: generate keys")
+ private_key = ec.generate_private_key(ec.SECP256R1())
+ dnskey = dns.dnssec.make_dnskey(
+ public_key=private_key.public_key(),
+ algorithm=dns.dnssec.Algorithm.ECDSAP256SHA256,
+ flags=257,
+ )
+
+ # Sign zone.
+ isctest.log.info(f"{zone}: sign zone")
+ now = datetime.now(timezone.utc)
+ inception = now - timedelta(hours=1)
+ expiration = now + timedelta(days=30)
+
+ for name, node in data.nodes.items():
+ owner = name.derelativize(origin)
+ rdatasets = list(node.rdatasets)
+
+ for rdataset in rdatasets:
+ rrset = dns.rrset.RRset(owner, rdataset.rdclass, rdataset.rdtype)
+ rrset.update(rdataset)
+
+ rrsig = dns.dnssec.sign(
+ rrset=rrset,
+ private_key=private_key,
+ signer=origin,
+ dnskey=dnskey,
+ inception=inception,
+ expiration=expiration,
+ deterministic=False,
+ )
+
+ rdataset = dns.rdataset.Rdataset(rrset.rdclass, dns.rdatatype.RRSIG)
+ rdataset.add(rrsig, rrset.ttl)
+ node.replace_rdataset(rdataset)
+
+ # Sign DNSKEY RRset.
+ dnskey_rrset = dns.rrset.RRset(origin, dns.rdataclass.IN, dns.rdatatype.DNSKEY)
+ dnskey_rrset.add(dnskey, ttl=TTL)
+
+ apex_node = data.nodes[origin]
+ apex_node.replace_rdataset(dnskey_rrset)
+
+ rrsig = dns.dnssec.sign(
+ rrset=dnskey_rrset,
+ private_key=private_key,
+ signer=origin,
+ dnskey=dnskey,
+ inception=inception,
+ expiration=expiration,
+ deterministic=False,
+ )
+ rdataset = dns.rdataset.Rdataset(rrset.rdclass, dns.rdatatype.RRSIG)
+ rdataset.add(rrsig, dnskey_rrset.ttl)
+ apex_node.replace_rdataset(rdataset)
+
+ # Output zone.
+ data.to_file(f"{ns}/{database}.signed", relativize=False)
+
+ # Output DS.
+ ds = dns.dnssec.make_ds(name=origin, key=dnskey, algorithm="SHA256")
+ with open(f"ns1/dsset-{zone}", "w", encoding="utf-8") as f:
+ f.write(f"{zone} {TTL} IN DS {ds.to_text()}\n")
+
+ sign_rogue_zone("ns3", "evil.test.", "evil.db")
+ sign_regular_zone("ns2", "victim.test.", "victim.db")
+ sign_regular_zone("ns1", "test.", "test.db")
+ root_ksk = sign_regular_zone("ns1", ".", "root.db")
+
+ return {
+ "root": root_ksk.into_ta("static-key"),
+ }
+
+
+def test_out_of_zone_nsec(ns4):
+ isctest.log.info("trying to poison aggressive nsec cache")
+ msg = isctest.query.create("nx.evil.test", "A")
+ res = isctest.query.tcp(msg, ns4.ip)
+ isctest.check.noadflag(res)
+
+ isctest.log.info("query victim from recursive")
+ msg = isctest.query.create("victim.test", "SOA")
+ res = isctest.query.tcp(msg, ns4.ip, attempts=1)
+ isctest.check.noerror(res)
+ isctest.check.adflag(res)
+ isctest.check.rr_count_eq(res.answer, 2)
+
+ isctest.log.info("checking for query history on victim nameserver")
+ with open("ns2/named.run", "r", encoding="utf-8") as f:
+ assert "(victim.test): query 'victim.test/SOA/IN' approved" in f.read()
--
2.55.0

View file

@ -0,0 +1,277 @@
From 72967445f37a01d28b4ecb0e8f907e22fddd5087 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ayd=C4=B1n=20Mercan?= <aydin@isc.org>
Date: Thu, 7 May 2026 18:59:20 +0300
Subject: [PATCH] Reject out-of-zone NSEC next owner names
When verifying DNSSEC records, make sure that a next owner name of
an NSEC record is a subdomain of the signer field.
This follows the specification RFC 4034, section 4.1.1:
Owner names of RRsets for which the given zone is not authoritative
(such as glue records) MUST NOT be listed in the Next Domain Name
unless at least one authoritative RRset exists at the same owner
name.
While the above paragraph is intended for glue records, it also
applies to out-of-zone data.
(cherry picked from commit 4065512d25b71605b9502bb69dfb903776d35aa9)
(cherry picked from commit 058023c66f11d78590d4aa8c4f98946c4c965e21)
change dns_nsec_requiredtypespresent to dns_nsec_is_legal
Change `dns_nsec_requiredtypespresent` to `dns_nsec_is_legal` as a
function for checking multiple NSEC validity rules.
Currently we now additionally check for out-of-zone NSEC entries.
(cherry picked from commit be2a6a497312469890b552907d039d2de0b44ccc)
(cherry picked from commit f751e19a30d107f04c2f644aff9f8dab8fed03ab)
---
lib/dns/dnssec.c | 13 ++++++++++
lib/dns/include/dns/dnssec.h | 6 +++++
lib/dns/include/dns/nsec.h | 18 ++++++++++----
lib/dns/nsec.c | 17 ++++++++++---
lib/dns/resolver.c | 48 ++++++++++++++++++++++++++++++++++--
lib/ns/query.c | 6 ++---
6 files changed, 94 insertions(+), 14 deletions(-)
diff --git a/lib/dns/dnssec.c b/lib/dns/dnssec.c
index 9b9b1f2bb2..5acaea9ecb 100644
--- a/lib/dns/dnssec.c
+++ b/lib/dns/dnssec.c
@@ -357,8 +357,10 @@ isc_result_t
dns_dnssec_verify(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
bool ignoretime, unsigned int maxbits, isc_mem_t *mctx,
dns_rdata_t *sigrdata, dns_name_t *wild) {
+ dns_rdata_nsec_t nsec;
dns_rdata_rrsig_t sig;
dns_fixedname_t fnewname;
+ dns_rdata_t rdata = DNS_RDATA_INIT;
isc_region_t r;
isc_buffer_t envbuf;
dns_rdata_t *rdatas;
@@ -464,6 +466,17 @@ dns_dnssec_verify(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
}
break;
}
+ /*
+ * Check for out of zone NSEC entries.
+ */
+ if (set->type == dns_rdatatype_nsec) {
+ RETERR(dns_rdataset_first(set));
+ dns_rdataset_current(set, &rdata);
+ RETERR(dns_rdata_tostruct(&rdata, &nsec, NULL));
+ if (!dns_name_issubdomain(&nsec.next, &sig.signer)) {
+ return DNS_R_NOVALIDNSEC;
+ }
+ }
again:
ret = dst_context_create(key, mctx, DNS_LOGCATEGORY_DNSSEC, false,
diff --git a/lib/dns/include/dns/dnssec.h b/lib/dns/include/dns/dnssec.h
index cb8fd9dc20..2be11b9144 100644
--- a/lib/dns/include/dns/dnssec.h
+++ b/lib/dns/include/dns/dnssec.h
@@ -151,6 +151,9 @@ dns_dnssec_verify(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
* this record, as this requires a resolver or database.
* If 'ignoretime' is true, temporal validity will not be checked.
*
+ * If 'set' is of type NSEC, this function also verifies that the
+ * Next Name is a subdomain of the Signer's Name from 'sigrdata'.
+ *
* 'maxbits' specifies the maximum number of rsa exponent bits accepted.
*
* Requires:
@@ -173,6 +176,9 @@ dns_dnssec_verify(const dns_name_t *name, dns_rdataset_t *set, dst_key_t *key,
*\li #DNS_R_KEYUNAUTHORIZED - the key cannot sign this data (either
* it is not a zone key or its flags prevent
* authentication)
+ *
+ *\li #DNS_R_NOVALIDNSEC - the NSEC rdata is not valid
+ *\li #DNS_R_KEYUNAUTHORIZED - the key cannot sign this data
*\li DST_R_*
*/
diff --git a/lib/dns/include/dns/nsec.h b/lib/dns/include/dns/nsec.h
index 50df8e45f1..1e71bf14e8 100644
--- a/lib/dns/include/dns/nsec.h
+++ b/lib/dns/include/dns/nsec.h
@@ -119,13 +119,21 @@ dns_nsec_noexistnodata(dns_rdatatype_t type, const dns_name_t *name,
*/
bool
-dns_nsec_requiredtypespresent(dns_rdataset_t *rdataset);
-/*
- * Return true if all the NSEC records in rdataset have both
- * NSEC and RRSIG present.
+dns_nsec_is_legal(dns_rdataset_t *rdataset, const dns_name_t *name);
+/**<
+ * \brief
+ * Validates a rdataset of type NSEC.
*
- * Requires:
+ * This functions checks for the following in the given rdataset:
+ * \li All NSEC records have both NSEC and RRSIG present
+ * \li All NSEC entries are under the `name`
+ *
+ * \par Requires:
* \li rdataset to be a NSEC rdataset.
+ * \li `name` is a valid dns_name_t
+ *
+ * \retval true if all the checks pass
+ * \retval false otherwise
*/
ISC_LANG_ENDDECLS
diff --git a/lib/dns/nsec.c b/lib/dns/nsec.c
index 80ee8d7d58..5abcce5f7f 100644
--- a/lib/dns/nsec.c
+++ b/lib/dns/nsec.c
@@ -21,6 +21,7 @@
#include <isc/util.h>
#include <dns/db.h>
+#include <dns/name.h>
#include <dns/nsec.h>
#include <dns/rdata.h>
#include <dns/rdatalist.h>
@@ -497,8 +498,9 @@ dns_nsec_noexistnodata(dns_rdatatype_t type, const dns_name_t *name,
}
bool
-dns_nsec_requiredtypespresent(dns_rdataset_t *nsecset) {
- dns_rdataset_t rdataset;
+dns_nsec_is_legal(dns_rdataset_t *nsecset, const dns_name_t *name) {
+ dns_rdataset_t rdataset = DNS_RDATASET_INIT;
+ dns_rdata_nsec_t nsec;
isc_result_t result;
bool found = false;
@@ -513,12 +515,19 @@ dns_nsec_requiredtypespresent(dns_rdataset_t *nsecset) {
{
dns_rdata_t rdata = DNS_RDATA_INIT;
dns_rdataset_current(&rdataset, &rdata);
- if (!dns_nsec_typepresent(&rdata, dns_rdatatype_nsec) ||
- !dns_nsec_typepresent(&rdata, dns_rdatatype_rrsig))
+
+ /* must never fail */
+ result = dns_rdata_tostruct(&rdata, &nsec, NULL);
+ INSIST(result == ISC_R_SUCCESS);
+
+ if (!dns_name_issubdomain(&nsec.next, name) ||
+ !dns_nsec_typepresent(&rdata, dns_rdatatype_rrsig) ||
+ !dns_nsec_typepresent(&rdata, dns_rdatatype_nsec))
{
dns_rdataset_disassociate(&rdataset);
return false;
}
+
found = true;
}
dns_rdataset_disassociate(&rdataset);
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 059ce53a9e..eac67f7a19 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -65,7 +65,9 @@
#include <dns/rootns.h>
#include <dns/stats.h>
#include <dns/tsig.h>
+#include <dns/types.h>
#include <dns/validator.h>
+#include <dns/view.h>
#include <dns/zone.h>
/* Detailed logging of fctx attach/detach */
@@ -5603,6 +5605,36 @@ fctx_setresult(fetchctx_t *fctx, dns_rdataset_t *rdataset) {
return result;
}
+static bool
+get_and_check_signer_name(dns_name_t *signer, dns_rdataset_t *sigrdataset) {
+ dns_rdata_rrsig_t rrsig;
+ isc_result_t result;
+ dns_rdata_t rdata;
+
+ if (dns_rdataset_first(sigrdataset) != ISC_R_SUCCESS) {
+ return false;
+ }
+
+ rdata = (dns_rdata_t)DNS_RDATA_INIT;
+ dns_rdataset_current(sigrdataset, &rdata);
+ result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
+ INSIST(result == ISC_R_SUCCESS);
+ dns_name_copy(&rrsig.signer, signer);
+
+ while (dns_rdataset_next(sigrdataset) == ISC_R_SUCCESS) {
+ rdata = (dns_rdata_t)DNS_RDATA_INIT;
+ dns_rdataset_current(sigrdataset, &rdata);
+ result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
+ INSIST(result == ISC_R_SUCCESS);
+
+ if (!dns_name_equal(signer, &rrsig.signer)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
/*
* The validator has finished.
*/
@@ -5633,6 +5665,8 @@ validated(isc_task_t *task, isc_event_t *event) {
dns_fixedname_t fwild;
dns_name_t *wild = NULL;
dns_message_t *message = NULL;
+ dns_fixedname_t fsigner;
+ dns_name_t *signer = NULL;
UNUSED(task); /* for now */
@@ -6021,10 +6055,20 @@ answer_response:
}
/*
- * Don't cache NSEC if missing NSEC or RRSIG types.
+ * Don't cache if all the RRSIGs don't have the same
+ * signer.
+ */
+ signer = dns_fixedname_initname(&fsigner);
+ if (!get_and_check_signer_name(signer, sigrdataset)) {
+ continue;
+ }
+
+ /*
+ * Don't cache NSEC if missing NSEC or RRSIG
+ * types.
*/
if (rdataset->type == dns_rdatatype_nsec &&
- !dns_nsec_requiredtypespresent(rdataset))
+ !dns_nsec_is_legal(rdataset, signer))
{
continue;
}
diff --git a/lib/ns/query.c b/lib/ns/query.c
index 2a2ba1daba..8bbcd7ff30 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -10370,10 +10370,10 @@ query_coveringnsec(query_ctx_t *qctx) {
}
/*
- * If NSEC or RRSIG are missing from the type map
- * reject the NSEC RRset.
+ * Check that the NSEC entry is legal.
+ * (NSEC + RRSIG present and the entry isn't out-of-zone)
*/
- if (!dns_nsec_requiredtypespresent(qctx->rdataset)) {
+ if (!dns_nsec_is_legal(qctx->rdataset, signer)) {
goto cleanup;
}
--
2.55.0

38
bind-chroot.tmpfiles.d Normal file
View file

@ -0,0 +1,38 @@
# vim: ft=conf:
# TODO: these definitions are in different form in rpm spec %files chroot section
# find a way to have it defined only once
#defattr(0664,root,named,-)
c /var/named/chroot/dev/null 0664 root named - 1:3
c /var/named/chroot/dev/random 0664 root named - 1:8
c /var/named/chroot/dev/urandom 0664 root named - 1:9
c /var/named/chroot/dev/zero 0664 root named - 1:5
#defattr(0640,root,named,0750)
d /var/named/chroot 0750 root named -
d /var/named/chroot/dev 0750 root named -
d /var/named/chroot/etc 0750 root named -
d /var/named/chroot/etc/named 0750 root named -
d /var/named/chroot/etc/pki 0750 root named -
d /var/named/chroot/etc/pki/dnssec-keys 0750 root named -
d /var/named/chroot/etc/crypto-policies 0750 root named -
d /var/named/chroot/etc/crypto-policies/back-ends 0750 root named -
d /var/named/chroot/var 0750 root named -
d /var/named/chroot/run 0750 root named -
#defattr(-,root,root,-)
d /var/named/chroot/usr - root root -
d /var/named/chroot/usr/lib64 - root root -
d /var/named/chroot/usr/lib64/bind - root root -
d /var/named/chroot/usr/lib64/named - root root -
d /var/named/chroot/usr/share/GeoIP - root root -
d /var/named/chroot/usr/share/named - root root -
d /var/named/chroot/proc - root root -
d /var/named/chroot/proc/sys - root root -
d /var/named/chroot/proc/sys/net - root root -
d /var/named/chroot/proc/sys/net/ipv4 - root root -
#defattr(0660,root,named,01770)
d /var/named/chroot/var/named 01770 root named -
#defattr(0660,named,named,0770)
d /var/named/chroot/var/tmp 0770 named named -
d /var/named/chroot/var/log 0770 named named -
#defattr(-,named,named,-)
d /var/named/chroot/run/named - named named -
L /var/named/chroot/var/run - named named - ../run

View file

@ -42,6 +42,8 @@
%global chroot_create_directories /dev /run/named %{_localstatedir}/{log,named,tmp} \\\
%{_sysconfdir}/{crypto-policies/back-ends,pki/dnssec-keys,named} \\\
%{_libdir}/bind %{_libdir}/named %{_datadir}/{GeoIP,named} /proc/sys/net/ipv4
%global upstream_sources 0 2
%global pgp_signature_sources 2
## The order of libs is important. See lib/Makefile.in for details
%define bind_export_libs isc dns isccfg irs
@ -85,8 +87,8 @@ License: MPL-2.0 AND ISC AND MIT AND BSD-3-Clause AND BSD-2-Clause
#
# Before rebasing bind, ensure bind-dyndb-ldap is ready to be rebuild and use side-tag with it.
# Updating just bind will cause freeipa-dns-server package to be uninstallable.
Version: 9.18.43
Release: 1%{?dist}
Version: 9.18.50
Release: 2%{?dist}
Epoch: 32
Url: https://www.isc.org/downloads/bind/
#
@ -111,12 +113,12 @@ Source37: named.service
Source38: named-chroot.service
Source41: setup-named-chroot.sh
Source42: generate-rndc-key.sh
Source43: named.rwtab
Source44: named-chroot-setup.service
Source46: named-setup-rndc.service
Source48: setup-named-softhsm.sh
Source49: named-chroot.files
Source50: named.sysusers
Source51: bind-chroot.tmpfiles.d
# Common patches
# FIXME: Is this still required?
@ -142,6 +144,31 @@ Patch32: bind-9.18-partial-additional-records.patch
Patch33: bind-9.18-dig-idn-input-always.patch
# downstream only too
Patch34: bind-9.18-dig-idn-input-always-test.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/4fd0755bdd08471f74e6e4c76cd2326f356e0a61
# https://gitlab.isc.org/isc-projects/bind9/-/work_items/5856
Patch36: bind-9.18-CVE-2026-11331.patch
Patch37: bind-9.18-CVE-2026-11331-test.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/c5d2fc706ca3635d9928c1cc68db73bffb35d772
Patch38: bind-9.18-CVE-2026-10822.patch
Patch40: bind-9.18-CVE-2026-10822-test.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/5a0cef5bdb077df73fa59504efb8ca4c8b0a84c5
Patch41: bind-9.18-CVE-2026-12617.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/26437be900c68bbe0974ec9ab804c2894c19c419
Patch42: bind-9.18-CVE-2026-12617-test.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/14d23a4955c62efe974266a8e96a8c5d7caad040
Patch43: bind-9.18-CVE-2026-11622.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/58812f64bf14b3930f5bb90a2d0e1f59bc8260b4
Patch44: bind-9.18-CVE-2026-11721.patch
Patch45: bind-9.18-CVE-2026-11721-test.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/348fd47f7636f610a39ba98427fcacab8e62389b
Patch46: bind-9.18-CVE-2026-10723.patch
Patch47: bind-9.18-CVE-2026-10723-test.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/b9ff2c9a36bb678fd1393d4f932b35a6882cd2a8
Patch48: bind-9.18-CVE-2026-13204.patch
Patch49: bind-9.18-CVE-2026-13204-test.patch
# https://gitlab.isc.org/isc-projects/bind9/commit/36f3d50f9c8ebc8d25ee033e707ca502e20b083f
Patch50: bind-9.18-CVE-2026-13321.patch
Patch51: bind-9.18-CVE-2026-13321-test.patch
%{?systemd_ordering}
# https://fedoraproject.org/wiki/Changes/RPMSuportForSystemdSysusers
@ -184,6 +211,7 @@ BuildRequires: softhsm
BuildRequires: perl(Net::DNS) perl(Net::DNS::Nameserver) perl(Time::HiRes) perl(Getopt::Long)
BuildRequires: perl(English)
BuildRequires: python3-dns
BuildRequires: python3-hypothesis
# manual configuration requires this tool
BuildRequires: iproute
%endif
@ -671,9 +699,7 @@ done
mkdir -p ${RPM_BUILD_ROOT}%{_tmpfilesdir}
install -p -m 644 %{SOURCE35} ${RPM_BUILD_ROOT}%{_tmpfilesdir}/named.conf
mkdir -p ${RPM_BUILD_ROOT}%{_sysconfdir}/rwtab.d
install -p -m 644 %{SOURCE43} ${RPM_BUILD_ROOT}%{_sysconfdir}/rwtab.d/named
install -p -m 644 %{SOURCE51} ${RPM_BUILD_ROOT}%{_tmpfilesdir}/%{name}-chroot.conf
%post
%?ldconfig
@ -768,7 +794,6 @@ fi;
%config(noreplace) %attr(0644,root,named) %{_sysconfdir}/named.ca
%config(noreplace) %{_sysconfdir}/logrotate.d/named
%{_tmpfilesdir}/named.conf
%{_sysconfdir}/rwtab.d/named
%{_unitdir}/named.service
%{_unitdir}/named-setup-rndc.service
%{_sysusersdir}/named.conf
@ -898,6 +923,7 @@ fi;
%{_unitdir}/named-chroot.service
%{_unitdir}/named-chroot-setup.service
%{_libexecdir}/setup-named-chroot.sh
%{_tmpfilesdir}/%{name}-chroot.conf
%defattr(0664,root,named,-)
%ghost %dev(c,1,3) %verify(not mtime) %{chroot_prefix}/dev/null
%ghost %dev(c,1,8) %verify(not mtime) %{chroot_prefix}/dev/random
@ -943,6 +969,36 @@ fi;
%endif
%changelog
* Tue Aug 25 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.50-2
- Potential wildcard CNAME RPZ policy bypass (CVE-2026-11331)
- Key Record using PRIVATEDNS algorithm may lead to exit (CVE-2026-10822)
- Record ordering based unexpected exit with CNAME or DNAME (CVE-2026-12617)
- Potential memory usage beyond configured limits (CVE-2026-11622)
- Cache poisoning via label count discrepancy, RRSIG, wildcards (CVE-2026-11721)
- Incorrect acceptance of NSEC3 records (CVE-2026-10723)
- Unexpected exit with NSEC and NSEC3 both present (CVE-2026-13204)
- DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field (CVE-2026-13321)
* Wed Jun 17 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.50-1
- Update to 9.18.50 (rhbz#2489833)
- Remove rwtab files
* Wed May 20 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.49-1
- Update to 9.18.49 (rhbz#2480121)
* Tue Apr 07 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.48-1
- Update to 9.18.48 (rhbz#2453853)
* Wed Mar 25 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.47-1
- Update to 9.18.47 (rhbz#2440561)
* Wed Jan 28 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.44-2
- Create /var/named directories for bind-chroot (RHEL-132053)
- Add forgotten _libdir/named into bind-chroot tmpfiles
* Thu Jan 22 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.44-1
- Update to 9.18.44 (rhbz#2431609)
* Wed Dec 17 2025 Petr Menšík <pemensik@redhat.com> - 32:9.18.43-1
- Update to 9.18.43 (rhbz#2415842)

View file

@ -1,6 +0,0 @@
dirs /var/named
files /var/named/named.ca
files /var/named/named.empty
files /var/named/named.localhost
files /var/named/named.loopback

View file

@ -1,2 +1,2 @@
SHA512 (bind-9.18.43.tar.xz) = 4f0e6849e883110f275739a03de20465c91563f26be94d380d28454f27d7c68fdc3ba0e1eaa8d25a6790cadc8228ee981dceb0a6fcf46ab4ffd24b8c76f42e25
SHA512 (bind-9.18.43.tar.xz.asc) = 82ecbbba5043793c5f5c6d7fd0166dbc60a9e7a349e396bb28f1be0c7643683e91e98cf2a84635d6c707c52273dd8df438df5601d06ea3a6be8293860d552f22
SHA512 (bind-9.18.50.tar.xz) = 5ae70c95f19868f41fd609bf34a908c38769401ee5b89e4782b94081032a579c00ba9010b2feb2789a95cfd12289cfe250e6488b3b47ff666bfa8cd7edf74d43
SHA512 (bind-9.18.50.tar.xz.asc) = 41df6df786cd33055a3fd6632ffd2968d6600e314140c547bba3452ec9f7726f44df27c3bd53a5a937ad11407d7391641e0b7b1aff7ebf87f25c65e2a76707b6