Fixed improper validation of array index of the component pppdump

Resolves: CVE-2022-4603

ppp-2.4.9-CVE-2022-4603.patch

@@ -0,0 +1,45 @@
+From a75fb7b198eed50d769c80c36629f38346882cbf Mon Sep 17 00:00:00 2001
+From: Paul Mackerras <paulus@ozlabs.org>
+Date: Thu, 4 Aug 2022 12:23:08 +1000
+Subject: [PATCH] pppdump: Avoid out-of-range access to packet buffer
+
+This fixes a potential vulnerability where data is written to spkt.buf
+and rpkt.buf without a check on the array index.  To fix this, we
+check the array index (pkt->cnt) before storing the byte or
+incrementing the count.  This also means we no longer have a potential
+signed integer overflow on the increment of pkt->cnt.
+
+Fortunately, pppdump is not used in the normal process of setting up a
+PPP connection, is not installed setuid-root, and is not invoked
+automatically in any scenario that I am aware of.
+
+Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
+---
+ pppdump/pppdump.c | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/pppdump/pppdump.c b/pppdump/pppdump.c
+index 2b815fc9b..b85a86271 100644
+--- a/pppdump/pppdump.c
++++ b/pppdump/pppdump.c
+@@ -297,6 +297,10 @@ dumpppp(f)
+ 			    printf("%s aborted packet:\n     ", dir);
+ 			    q = "    ";
+ 			}
++			if (pkt->cnt >= sizeof(pkt->buf)) {
++			    printf("%s over-long packet truncated:\n     ", dir);
++			    q = "    ";
++			}
+ 			nb = pkt->cnt;
+ 			p = pkt->buf;
+ 			pkt->cnt = 0;
+@@ -400,7 +404,8 @@ dumpppp(f)
+ 			c ^= 0x20;
+ 			pkt->esc = 0;
+ 		    }
+-		    pkt->buf[pkt->cnt++] = c;
++		    if (pkt->cnt < sizeof(pkt->buf))
++			pkt->buf[pkt->cnt++] = c;
+ 		    break;
+ 		}
+ 	    }

ppp.spec

@@ -2,7 +2,7 @@
 
 Name:    ppp
 Version: 2.4.9
-Release: 9%{?dist}
+Release: 10%{?dist}
 Summary: The Point-to-Point Protocol daemon
 License: BSD and LGPLv2+ and GPLv2+ and Public Domain
 URL:     http://www.samba.org/ppp
@@ -43,6 +43,8 @@ Patch0027:     ppp-2.4.9-pppd-eap-Fix-bug-causing-incorrect-response-length-3.pa
 Patch0028:     ppp-2.4.9-pppd-Fix-logical-error-in-comparing-valid-encryption.patch
 # https://github.com/ppp-project/ppp/pull/267/commits/6bfe06b9428a60eb637d5450d65dd3932fe5a83f
 Patch0029:     ppp-2.4.9-pppd-Expose-the-MPPE-keys-generated-through-an-API-2.patch
+# https://github.com/ppp-project/ppp/commit/a75fb7b198eed50d769c80c36629f38346882cbf
+Patch0030:     ppp-2.4.9-CVE-2022-4603.patch
 
 BuildRequires: make
 BuildRequires: gcc
@@ -173,6 +175,10 @@ mkdir -p %{buildroot}%{_rundir}/ppp
 %doc PLUGINS
 
 %changelog
+* Thu Jan  4 2024 Jaroslav Škarvada <jskarvad@redhat.com> - 2.4.9-10
+- Fixed improper validation of array index of the component pppdump
+  Resolves: CVE-2022-4603
+
 * Fri Jan 20 2023 Fedora Release Engineering <releng@fedoraproject.org> - 2.4.9-9
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild