File iconv-iso-2022-cn-ext.patch of Package glibc.33856
From 682ad4c8623e611a971839990ceef00346289cc9 Mon Sep 17 00:00:00 2001
From: Charles Fol <folcharles@gmail.com>
Date: Thu, 28 Mar 2024 12:25:38 -0300
Subject: [PATCH] iconv: ISO-2022-CN-EXT: fix out-of-bound writes when writing
escape sequence (CVE-2024-2961)
ISO-2022-CN-EXT uses escape sequences to indicate character set changes
(as specified by RFC 1922). While the SOdesignation has the expected
bounds checks, neither SS2designation nor SS3designation have its;
allowing a write overflow of 1, 2, or 3 bytes with fixed values:
'$+I', '$+J', '$+K', '$+L', '$+M', or '$*H'.
Checked on aarch64-linux-gnu.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit f9dc609e06b1136bb0408be9605ce7973a767ada)
---
iconvdata/Makefile | 5 +-
iconvdata/iso-2022-cn-ext.c | 12 +++
iconvdata/tst-iconv-iso-2022-cn-ext.c | 128 ++++++++++++++++++++++++++
3 files changed, 144 insertions(+), 1 deletion(-)
create mode 100644 iconvdata/tst-iconv-iso-2022-cn-ext.c
Index: glibc-2.22/iconvdata/iso-2022-cn-ext.c
===================================================================
--- glibc-2.22.orig/iconvdata/iso-2022-cn-ext.c
+++ glibc-2.22/iconvdata/iso-2022-cn-ext.c
@@ -564,6 +564,12 @@ enum
{ \
const char *escseq; \
\
+ if (outptr + 4 > outend) \
+ { \
+ result = __GCONV_FULL_OUTPUT; \
+ break; \
+ } \
+ \
assert (used == CNS11643_2_set); /* XXX */ \
escseq = "*H"; \
*outptr++ = ESC; \
@@ -577,6 +583,12 @@ enum
{ \
const char *escseq; \
\
+ if (outptr + 4 > outend) \
+ { \
+ result = __GCONV_FULL_OUTPUT; \
+ break; \
+ } \
+ \
assert ((used >> 5) >= 3 && (used >> 5) <= 7); \
escseq = "+I+J+K+L+M" + ((used >> 5) - 3) * 2; \
*outptr++ = ESC; \
