From ee7a3144c9922808181009b7b3e50e852fb4999b Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Mon, 21 Dec 2020 08:56:43 +0530 Subject: [PATCH] Fix buffer overrun in EUC-KR conversion module (bz #24973) The byte 0xfe as input to the EUC-KR conversion denotes a user-defined area and is not allowed. The from_euc_kr function used to skip two bytes when told to skip over the unknown designation, potentially running over the buffer end. Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=patch;h=ee7a3144c9922808181009b7b3e50e852fb4999b] CVE: CVE-2019-25013 Signed-off-by: Scott Murray --- iconvdata/Makefile | 3 ++- iconvdata/bug-iconv13.c | 53 +++++++++++++++++++++++++++++++++++++++++ iconvdata/euc-kr.c | 6 +---- iconvdata/ksc5601.h | 6 ++--- 4 files changed, 59 insertions(+), 9 deletions(-) create mode 100644 iconvdata/bug-iconv13.c diff --git a/iconvdata/Makefile b/iconvdata/Makefile index 4ec2741cdc..85009f3390 100644 --- a/iconvdata/Makefile +++ b/iconvdata/Makefile @@ -73,7 +73,8 @@ modules.so := $(addsuffix .so, $(modules)) ifeq (yes,$(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-iconv10 bug-iconv11 bug-iconv12 tst-iconv-big5-hkscs-to-2ucs4 \ + bug-iconv13 ifeq ($(have-thread-library),yes) tests += bug-iconv3 endif diff --git a/iconvdata/bug-iconv13.c b/iconvdata/bug-iconv13.c new file mode 100644 index 0000000000..87aaff398e --- /dev/null +++ b/iconvdata/bug-iconv13.c @@ -0,0 +1,53 @@ +/* bug 24973: Test EUC-KR module + Copyright (C) 2020 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 + . */ + +#include +#include +#include +#include + +static int +do_test (void) +{ + iconv_t cd = iconv_open ("UTF-8//IGNORE", "EUC-KR"); + TEST_VERIFY_EXIT (cd != (iconv_t) -1); + + /* 0xfe (->0x7e : row 94) and 0xc9 (->0x49 : row 41) are user-defined + areas, which are not allowed and should be skipped over due to + //IGNORE. The trailing 0xfe also is an incomplete sequence, which + should be checked first. */ + char input[4] = { '\xc9', '\xa1', '\0', '\xfe' }; + char *inptr = input; + size_t insize = sizeof (input); + char output[4]; + char *outptr = output; + size_t outsize = sizeof (output); + + /* This used to crash due to buffer overrun. */ + TEST_VERIFY (iconv (cd, &inptr, &insize, &outptr, &outsize) == (size_t) -1); + TEST_VERIFY (errno == EINVAL); + /* The conversion should produce one character, the converted null + character. */ + TEST_VERIFY (sizeof (output) - outsize == 1); + + TEST_VERIFY_EXIT (iconv_close (cd) != -1); + + return 0; +} + +#include diff --git a/iconvdata/euc-kr.c b/iconvdata/euc-kr.c index b0d56cf3ee..1045bae926 100644 --- a/iconvdata/euc-kr.c +++ b/iconvdata/euc-kr.c @@ -80,11 +80,7 @@ euckr_from_ucs4 (uint32_t ch, unsigned char *cp) \ if (ch <= 0x9f) \ ++inptr; \ - /* 0xfe(->0x7e : row 94) and 0xc9(->0x59 : row 41) are \ - user-defined areas. */ \ - else if (__builtin_expect (ch == 0xa0, 0) \ - || __builtin_expect (ch > 0xfe, 0) \ - || __builtin_expect (ch == 0xc9, 0)) \ + else if (__glibc_unlikely (ch == 0xa0)) \ { \ /* This is illegal. */ \ STANDARD_FROM_LOOP_ERR_HANDLER (1); \ diff --git a/iconvdata/ksc5601.h b/iconvdata/ksc5601.h index d3eb3a4ff8..f5cdc72797 100644 --- a/iconvdata/ksc5601.h +++ b/iconvdata/ksc5601.h @@ -50,15 +50,15 @@ ksc5601_to_ucs4 (const unsigned char **s, size_t avail, unsigned char offset) unsigned char ch2; int idx; + if (avail < 2) + return 0; + /* row 94(0x7e) and row 41(0x49) are user-defined area in KS C 5601 */ if (ch < offset || (ch - offset) <= 0x20 || (ch - offset) >= 0x7e || (ch - offset) == 0x49) return __UNKNOWN_10646_CHAR; - if (avail < 2) - return 0; - ch2 = (*s)[1]; if (ch2 < offset || (ch2 - offset) <= 0x20 || (ch2 - offset) >= 0x7f) return __UNKNOWN_10646_CHAR; -- 2.27.0