public inbox for glibc-cvs@sourceware.org help / color / mirror / Atom feed
From: Adhemerval Zanella <azanella@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/release/2.34/master] iconv: ISO-2022-CN-EXT: fix out-of-bound writes when writing escape sequence (CVE-2024-2961) Date: Wed, 17 Apr 2024 17:06:18 +0000 (GMT) [thread overview] Message-ID: <20240417170619.029E73858C52@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a8b0561db4b9847ebfbfec20075697d5492a363c commit a8b0561db4b9847ebfbfec20075697d5492a363c Author: Charles Fol <folcharles@gmail.com> Date: Thu Mar 28 12:25:38 2024 -0300 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) Diff: --- 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(-) diff --git a/iconvdata/Makefile b/iconvdata/Makefile index d5507a048c..499584a49c 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 2aca91c021..c1339fe933 100644 --- a/iconvdata/iso-2022-cn-ext.c +++ b/iconvdata/iso-2022-cn-ext.c @@ -575,6 +575,12 @@ 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; \ @@ -588,6 +594,12 @@ 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>
reply other threads:[~2024-04-17 17:06 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20240417170619.029E73858C52@sourceware.org \ --to=azanella@sourceware.org \ --cc=glibc-cvs@sourceware.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).