From 3b741e99d4050fb6b8f76109b042f0ed419788b4 Mon Sep 17 00:00:00 2001
From: Yang Yanchao <yangyanchao6@huawei.com>
Date: Tue, 23 Apr 2024 10:45:52 +0800
Subject: [PATCH] iconv: ISO-2022-CN-EXT: fix out-of-bound writes when writing
 escape sequence (CVE-2024-2961)

Signed-off-by: Chen Jun <chenjun102@huawei.com>
---
 glibc.spec                                    |   6 +-
 ...N-EXT-fix-out-of-bound-writes-when-w.patch | 214 ++++++++++++++++++
 2 files changed, 219 insertions(+), 1 deletion(-)
 create mode 100644 iconv-ISO-2022-CN-EXT-fix-out-of-bound-writes-when-w.patch

diff --git a/iconv-ISO-2022-CN-EXT-fix-out-of-bound-writes-when-w.patch b/iconv-ISO-2022-CN-EXT-fix-out-of-bound-writes-when-w.patch
new file mode 100644
index 0000000..4e39cca
--- /dev/null
+++ b/iconv-ISO-2022-CN-EXT-fix-out-of-bound-writes-when-w.patch
@@ -0,0 +1,214 @@
+From f9dc609e06b1136bb0408be9605ce7973a767ada 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>
+---
+ 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
+
+diff --git a/iconvdata/Makefile b/iconvdata/Makefile
+index ea019ce5c0..7196a8744b 100644
+--- a/iconvdata/Makefile
++++ b/iconvdata/Makefile
+@@ -75,7 +75,8 @@ ifeq (yes,$(build-shared))
+ tests = bug-iconv1 bug-iconv2 tst-loading tst-e2big tst-iconv4 bug-iconv4 \
+ 	tst-iconv6 bug-iconv5 bug-iconv6 tst-iconv7 bug-iconv8 bug-iconv9 \
+ 	bug-iconv10 bug-iconv11 bug-iconv12 tst-iconv-big5-hkscs-to-2ucs4 \
+-	bug-iconv13 bug-iconv14 bug-iconv15
++	bug-iconv13 bug-iconv14 bug-iconv15 \
++	tst-iconv-iso-2022-cn-ext
+ ifeq ($(have-thread-library),yes)
+ tests += bug-iconv3
+ endif
+@@ -330,6 +331,8 @@ $(objpfx)bug-iconv14.out: $(addprefix $(objpfx), $(gconv-modules)) \
+ 			  $(addprefix $(objpfx),$(modules.so))
+ $(objpfx)bug-iconv15.out: $(addprefix $(objpfx), $(gconv-modules)) \
+ 			  $(addprefix $(objpfx),$(modules.so))
++$(objpfx)tst-iconv-iso-2022-cn-ext.out: $(addprefix $(objpfx), $(gconv-modules)) \
++					$(addprefix $(objpfx),$(modules.so))
+ 
+ $(objpfx)iconv-test.out: run-iconv-test.sh \
+ 			 $(addprefix $(objpfx), $(gconv-modules)) \
+diff --git a/iconvdata/iso-2022-cn-ext.c b/iconvdata/iso-2022-cn-ext.c
+index b34c8a36f4..cce29b1969 100644
+--- a/iconvdata/iso-2022-cn-ext.c
++++ b/iconvdata/iso-2022-cn-ext.c
+@@ -574,6 +574,12 @@ DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
+ 	      {								      \
+ 		const char *escseq;					      \
+ 									      \
++		if (outptr + 4 > outend)				      \
++		  {							      \
++		    result = __GCONV_FULL_OUTPUT;			      \
++		    break;						      \
++		  }							      \
++									      \
+ 		assert (used == CNS11643_2_set); /* XXX */		      \
+ 		escseq = "*H";						      \
+ 		*outptr++ = ESC;					      \
+@@ -587,6 +593,12 @@ DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
+ 	      {								      \
+ 		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;					      \
+diff --git a/iconvdata/tst-iconv-iso-2022-cn-ext.c b/iconvdata/tst-iconv-iso-2022-cn-ext.c
+new file mode 100644
+index 0000000000..96a8765fd5
+--- /dev/null
++++ b/iconvdata/tst-iconv-iso-2022-cn-ext.c
+@@ -0,0 +1,128 @@
++/* Verify ISO-2022-CN-EXT does not write out of the bounds.
++   Copyright (C) 2024 Free Software Foundation, Inc.
++   This file is part of the GNU C Library.
++
++   The GNU C Library is free software; you can redistribute it and/or
++   modify it under the terms of the GNU Lesser General Public
++   License as published by the Free Software Foundation; either
++   version 2.1 of the License, or (at your option) any later version.
++
++   The GNU C Library is distributed in the hope that it will be useful,
++   but WITHOUT ANY WARRANTY; without even the implied warranty of
++   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
++   Lesser General Public License for more details.
++
++   You should have received a copy of the GNU Lesser General Public
++   License along with the GNU C Library; if not, see
++   <https://www.gnu.org/licenses/>.  */
++
++#include <stdio.h>
++#include <string.h>
++
++#include <errno.h>
++#include <iconv.h>
++#include <sys/mman.h>
++
++#include <support/xunistd.h>
++#include <support/check.h>
++#include <support/support.h>
++
++/* The test sets up a two memory page buffer with the second page marked
++   PROT_NONE to trigger a fault if the conversion writes beyond the exact
++   expected amount.  Then we carry out various conversions and precisely
++   place the start of the output buffer in order to trigger a SIGSEGV if the
++   process writes anywhere between 1 and page sized bytes more (only one
++   PROT_NONE page is setup as a canary) than expected.  These tests exercise
++   all three of the cases in ISO-2022-CN-EXT where the converter must switch
++   character sets and may run out of buffer space while doing the
++   operation.  */
++
++static int
++do_test (void)
++{
++  iconv_t cd = iconv_open ("ISO-2022-CN-EXT", "UTF-8");
++  TEST_VERIFY_EXIT (cd != (iconv_t) -1);
++
++  char *ntf;
++  size_t ntfsize;
++  char *outbufbase;
++  {
++    int pgz = getpagesize ();
++    TEST_VERIFY_EXIT (pgz > 0);
++    ntfsize = 2 * pgz;
++
++    ntf = xmmap (NULL, ntfsize, PROT_READ | PROT_WRITE, MAP_PRIVATE
++		 | MAP_ANONYMOUS, -1);
++    xmprotect (ntf + pgz, pgz, PROT_NONE);
++
++    outbufbase = ntf + pgz;
++  }
++
++  /* Check if SOdesignation escape sequence does not trigger an OOB write.  */
++  {
++    char inbuf[] = "\xe4\xba\xa4\xe6\x8d\xa2";
++
++    for (int i = 0; i < 9; i++)
++      {
++	char *inp = inbuf;
++	size_t inleft = sizeof (inbuf) - 1;
++
++	char *outp = outbufbase - i;
++	size_t outleft = i;
++
++	TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
++			  == (size_t) -1);
++	TEST_COMPARE (errno, E2BIG);
++
++	TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
++      }
++  }
++
++  /* Same as before for SS2designation.  */
++  {
++    char inbuf[] = "㴽 \xe3\xb4\xbd";
++
++    for (int i = 0; i < 14; i++)
++      {
++	char *inp = inbuf;
++	size_t inleft = sizeof (inbuf) - 1;
++
++	char *outp = outbufbase - i;
++	size_t outleft = i;
++
++	TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
++			  == (size_t) -1);
++	TEST_COMPARE (errno, E2BIG);
++
++	TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
++      }
++  }
++
++  /* Same as before for SS3designation.  */
++  {
++    char inbuf[] = "劄 \xe5\x8a\x84";
++
++    for (int i = 0; i < 14; i++)
++      {
++	char *inp = inbuf;
++	size_t inleft = sizeof (inbuf) - 1;
++
++	char *outp = outbufbase - i;
++	size_t outleft = i;
++
++	TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
++			  == (size_t) -1);
++	TEST_COMPARE (errno, E2BIG);
++
++	TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
++      }
++  }
++
++  TEST_VERIFY_EXIT (iconv_close (cd) != -1);
++
++  xmunmap (ntf, ntfsize);
++
++  return 0;
++}
++
++#include <support/test-driver.c>
+-- 
+2.33.0
+
-- 
2.33.0

