mirror/glibc
2
0
Fork 0
mirror of git://sourceware.org/git/glibc.git synced 2025-02-23 13:09:58 +08:00
Code Issues Packages Projects Releases Wiki Activity

x86-64 strnlen/wcsnlen: Properly handle the length parameter [BZ #24097]

Browse Source 
On x32, the size_t parameter may be passed in the lower 32 bits of a
64-bit register with the non-zero upper 32 bits.  The string/memory
functions written in assembly can only use the lower 32 bits of a
64-bit register as length or must clear the upper 32 bits before using
the full 64-bit register for length.

This pach fixes strnlen/wcsnlen for x32.  Tested on x86-64 and x32.  On
x86-64, libc.so is the same with and withou the fix.

	[BZ #24097]
	CVE-2019-6488
	* sysdeps/x86_64/multiarch/strlen-avx2.S: Use RSI_LP for length.
	Clear the upper 32 bits of RSI register.
	* sysdeps/x86_64/strlen.S: Use RSI_LP for length.
	* sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-strnlen
	and tst-size_t-wcsnlen.
	* sysdeps/x86_64/x32/tst-size_t-strnlen.c: New file.
	* sysdeps/x86_64/x32/tst-size_t-wcsnlen.c: Likewise.

(cherry picked from commit 5165de69c0)
This commit is contained in:
H.J. Lu 2019-02-01 12:24:08 -08:00
parent 40575878cd
commit dc968f5573
6 changed files with 118 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
ChangeLog
View File

@ -1,3 +1,15 @@
2019-02-01 H.J. Lu <hongjiu.lu@intel.com>
[BZ #24097]
CVE-2019-6488
* sysdeps/x86_64/multiarch/strlen-avx2.S: Use RSI_LP for length.
Clear the upper 32 bits of RSI register.
* sysdeps/x86_64/strlen.S: Use RSI_LP for length.
* sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-strnlen
and tst-size_t-wcsnlen.
* sysdeps/x86_64/x32/tst-size_t-strnlen.c: New file.
* sysdeps/x86_64/x32/tst-size_t-wcsnlen.c: Likewise.
2019-02-01 H.J. Lu <hongjiu.lu@intel.com>
[BZ #24097]

9
sysdeps/x86_64/multiarch/strlen-avx2.S
View File

@ -42,12 +42,15 @@
ENTRY (STRLEN)
# ifdef USE_AS_STRNLEN
/* Check for zero length. */
testq %rsi, %rsi
test %RSI_LP, %RSI_LP
jz L(zero)
# ifdef USE_AS_WCSLEN
shl $2, %rsi
shl $2, %RSI_LP
# elif defined __ILP32__
/* Clear the upper 32 bits. */
movl %esi, %esi
# endif
movq %rsi, %r8
mov %RSI_LP, %R8_LP
# endif
movl %edi, %ecx
movq %rdi, %rdx

12
sysdeps/x86_64/strlen.S
View File

@ -59,21 +59,21 @@ ENTRY(strlen)
#ifdef AS_STRNLEN
/* Do not read anything when n==0. */
test %rsi, %rsi
test %RSI_LP, %RSI_LP
jne L(n_nonzero)
xor %rax, %rax
ret
L(n_nonzero):
# ifdef AS_WCSLEN
shlq $2, %rsi
shl $2, %RSI_LP
# endif
/* Initialize long lived registers. */
add %rdi, %rsi
mov %rsi, %r10
and $-64, %r10
mov %rsi, %r11
add %RDI_LP, %RSI_LP
mov %RSI_LP, %R10_LP
and $-64, %R10_LP
mov %RSI_LP, %R11_LP
#endif
pxor %xmm0, %xmm0

4
sysdeps/x86_64/x32/Makefile
View File

@ -8,10 +8,10 @@ endif
ifeq ($(subdir),string)
tests += tst-size_t-memchr tst-size_t-memcmp tst-size_t-memcpy \
tst-size_t-memrchr tst-size_t-memset tst-size_t-strncasecmp \
tst-size_t-strncmp tst-size_t-strncpy
tst-size_t-strncmp tst-size_t-strncpy tst-size_t-strnlen
endif
ifeq ($(subdir),wcsmbs)
tests += tst-size_t-wmemchr tst-size_t-wmemcmp tst-size_t-wmemset \
tst-size_t-wcsncmp
tst-size_t-wcsncmp tst-size_t-wcsnlen
endif

72
sysdeps/x86_64/x32/tst-size_t-strnlen.c Normal file
View File

@ -0,0 +1,72 @@
/* Test strnlen with size_t in the lower 32 bits of 64-bit register.
Copyright (C) 2019 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
<http://www.gnu.org/licenses/>. */
#ifdef WIDE
# define TEST_NAME "wcsnlen"
#else
# define TEST_NAME "strnlen"
#endif /* WIDE */
#include "test-size_t.h"
#ifdef WIDE
# include <wchar.h>
# define STRNLEN wcsnlen
# define CHAR wchar_t
#else
# define STRNLEN strnlen
# define CHAR char
#endif /* WIDE */
IMPL (STRNLEN, 1)
typedef size_t (*proto_t) (const CHAR *, size_t);
static size_t
__attribute__ ((noinline, noclone))
do_strnlen (parameter_t a, parameter_t b)
{
return CALL (&a, a.p, b.len);
}
static int
test_main (void)
{
test_init ();
size_t size = page_size / sizeof (CHAR);
parameter_t src = { { 0 }, buf2 };
parameter_t c = { { size }, (void *) (uintptr_t) 'a' };
int ret = 0;
FOR_EACH_IMPL (impl, 0)
{
src.fn = impl->fn;
size_t res = do_strnlen (src, c);
if (res != size)
{
error (0, 0, "Wrong result in function %s: 0x%x != 0x%x",
impl->name, res, size);
ret = 1;
}
}
return ret ? EXIT_FAILURE : EXIT_SUCCESS;
}
#include <support/test-driver.c>

20
sysdeps/x86_64/x32/tst-size_t-wcsnlen.c Normal file
View File

@ -0,0 +1,20 @@
/* Test wcsnlen with size_t in the lower 32 bits of 64-bit register.
Copyright (C) 2019 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
<http://www.gnu.org/licenses/>. */
#define WIDE 1
#include "tst-size_t-strnlen.c"