Don't write beyond destination in __mempcpy_avx512_no_vzeroupper (bug 23196)

When compiled as mempcpy, the return value is the end of the destination
buffer, thus it cannot be used to refer to the start of it.
This commit is contained in:
Andreas Schwab 2018-05-22 10:37:59 +02:00
parent 8f145c7712
commit 9aaaab7c6e
3 changed files with 13 additions and 2 deletions

View File

@ -1,3 +1,12 @@
2018-05-23 Andreas Schwab <schwab@suse.de>
[BZ #23196]
CVE-2018-11237
* sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S
(L(preloop_large)): Save initial destination pointer in %r11 and
use it instead of %rax after the loop.
* string/test-mempcpy.c (MIN_PAGE_SIZE): Define.
2018-05-22 Joseph Myers <joseph@codesourcery.com>
* sysdeps/aarch64/Implies: Remove aarch64/soft-fp.

View File

@ -18,6 +18,7 @@
<http://www.gnu.org/licenses/>. */
#define MEMCPY_RESULT(dst, len) (dst) + (len)
#define MIN_PAGE_SIZE 131072
#define TEST_MAIN
#define TEST_NAME "mempcpy"
#include "test-string.h"

View File

@ -336,6 +336,7 @@ L(preloop_large):
vmovups (%rsi), %zmm4
vmovups 0x40(%rsi), %zmm5
mov %rdi, %r11
/* Align destination for access with non-temporal stores in the loop. */
mov %rdi, %r8
and $-0x80, %rdi
@ -366,8 +367,8 @@ L(gobble_256bytes_nt_loop):
cmp $256, %rdx
ja L(gobble_256bytes_nt_loop)
sfence
vmovups %zmm4, (%rax)
vmovups %zmm5, 0x40(%rax)
vmovups %zmm4, (%r11)
vmovups %zmm5, 0x40(%r11)
jmp L(check)
L(preloop_large_bkw):