CVE-2022-45061: CPU denial of service via inefficient IDNA decoder

00394-cve-2022-45061-cpu-denial-of-service-via-inefficient-idna-decoder.patch

@@ -0,0 +1,95 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Miss Islington (bot)"
+ <31488909+miss-islington@users.noreply.github.com>
+Date: Mon, 7 Nov 2022 19:22:14 -0800
+Subject: [PATCH] 00394: CVE-2022-45061: CPU denial of service via inefficient
+ IDNA decoder
+
+gh-98433: Fix quadratic time idna decoding.
+
+There was an unnecessary quadratic loop in idna decoding. This restores
+the behavior to linear.
+
+(cherry picked from commit a6f6c3a3d6f2b580f2d87885c9b8a9350ad7bf15)
+
+Co-authored-by: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
+Co-authored-by: Gregory P. Smith <greg@krypto.org>
+---
+ Lib/encodings/idna.py                         | 32 +++++++++----------
+ Lib/test/test_codecs.py                       |  6 ++++
+ ...2-11-04-09-29-36.gh-issue-98433.l76c5G.rst |  6 ++++
+ 3 files changed, 27 insertions(+), 17 deletions(-)
+ create mode 100644 Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst
+
+diff --git a/Lib/encodings/idna.py b/Lib/encodings/idna.py
+index ea4058512f..bf98f51336 100644
+--- a/Lib/encodings/idna.py
++++ b/Lib/encodings/idna.py
+@@ -39,23 +39,21 @@ def nameprep(label):
+ 
+     # Check bidi
+     RandAL = [stringprep.in_table_d1(x) for x in label]
+-    for c in RandAL:
+-        if c:
+-            # There is a RandAL char in the string. Must perform further
+-            # tests:
+-            # 1) The characters in section 5.8 MUST be prohibited.
+-            # This is table C.8, which was already checked
+-            # 2) If a string contains any RandALCat character, the string
+-            # MUST NOT contain any LCat character.
+-            if any(stringprep.in_table_d2(x) for x in label):
+-                raise UnicodeError("Violation of BIDI requirement 2")
+-
+-            # 3) If a string contains any RandALCat character, a
+-            # RandALCat character MUST be the first character of the
+-            # string, and a RandALCat character MUST be the last
+-            # character of the string.
+-            if not RandAL[0] or not RandAL[-1]:
+-                raise UnicodeError("Violation of BIDI requirement 3")
++    if any(RandAL):
++        # There is a RandAL char in the string. Must perform further
++        # tests:
++        # 1) The characters in section 5.8 MUST be prohibited.
++        # This is table C.8, which was already checked
++        # 2) If a string contains any RandALCat character, the string
++        # MUST NOT contain any LCat character.
++        if any(stringprep.in_table_d2(x) for x in label):
++            raise UnicodeError("Violation of BIDI requirement 2")
++        # 3) If a string contains any RandALCat character, a
++        # RandALCat character MUST be the first character of the
++        # string, and a RandALCat character MUST be the last
++        # character of the string.
++        if not RandAL[0] or not RandAL[-1]:
++            raise UnicodeError("Violation of BIDI requirement 3")
+ 
+     return label
+ 
+diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py
+index 56485de3f6..a798d1f287 100644
+--- a/Lib/test/test_codecs.py
++++ b/Lib/test/test_codecs.py
+@@ -1640,6 +1640,12 @@ class IDNACodecTest(unittest.TestCase):
+         self.assertEqual("pyth\xf6n.org".encode("idna"), b"xn--pythn-mua.org")
+         self.assertEqual("pyth\xf6n.org.".encode("idna"), b"xn--pythn-mua.org.")
+ 
++    def test_builtin_decode_length_limit(self):
++        with self.assertRaisesRegex(UnicodeError, "too long"):
++            (b"xn--016c"+b"a"*1100).decode("idna")
++        with self.assertRaisesRegex(UnicodeError, "too long"):
++            (b"xn--016c"+b"a"*70).decode("idna")
++
+     def test_stream(self):
+         r = codecs.getreader("idna")(io.BytesIO(b"abc"))
+         r.read(3)
+diff --git a/Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst b/Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst
+new file mode 100644
+index 0000000000..5185fac2e2
+--- /dev/null
++++ b/Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst
+@@ -0,0 +1,6 @@
++The IDNA codec decoder used on DNS hostnames by :mod:`socket` or :mod:`asyncio`
++related name resolution functions no longer involves a quadratic algorithm.
++This prevents a potential CPU denial of service if an out-of-spec excessive
++length hostname involving bidirectional characters were decoded. Some protocols
++such as :mod:`urllib` http ``3xx`` redirects potentially allow for an attacker
++to supply such a name.

python3.6.spec

@@ -17,7 +17,7 @@ URL: https://www.python.org/
 #global prerel ...
 %global upstream_version %{general_version}%{?prerel}
 Version: %{general_version}%{?prerel:~%{prerel}}
-Release: 14%{?dist}
+Release: 15%{?dist}
 License: Python
 
 
@@ -569,6 +569,15 @@ Patch387: 00387-cve-2020-10735-prevent-dos-by-very-large-int.patch
 # [2]: https://mouha.be/sha-3-buffer-overflow/
 Patch392: 00392-cve-2022-37454-fix-buffer-overflows-in-_sha3-module.patch
 
+# 00394 # 377cbc015f738fdea510969d0dbe266748b6bb09
+# CVE-2022-45061: CPU denial of service via inefficient IDNA decoder
+#
+# gh-98433: Fix quadratic time idna decoding.
+#
+# There was an unnecessary quadratic loop in idna decoding. This restores
+# the behavior to linear.
+Patch394: 00394-cve-2022-45061-cpu-denial-of-service-via-inefficient-idna-decoder.patch
+
 # (New patches go here ^^^)
 #
 # When adding new patches to "python" and "python3" in Fedora, EL, etc.,
@@ -1759,6 +1768,10 @@ CheckPython optimized
 # ======================================================
 
 %changelog
+* Mon Dec 19 2022 Charalampos Stratakis <cstratak@redhat.com> - 3.6.15-15
+- Security fix for CVE-2022-45061: CPU denial of service via inefficient IDNA decoder
+  Related: rhbz#2144072
+
 * Thu Nov 10 2022 Miro Hrončok <mhroncok@redhat.com> - 3.6.15-14
 - CVE-2022-37454: Fix buffer overflows in _sha3 module
   Related: rhbz#2140200