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.
This commit is contained in:
Andreas Schwab 2020-12-21 08:56:43 +05:30 committed by Siddhesh Poyarekar
parent e0aec6c833
commit ee7a3144c9
4 changed files with 59 additions and 9 deletions

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@ -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

53
iconvdata/bug-iconv13.c Normal file
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@ -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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <iconv.h>
#include <stdio.h>
#include <support/check.h>
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 <support/test-driver.c>

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@ -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); \

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@ -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;