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authorAndreas Schwab <schwab@suse.de>2018-05-22 10:37:59 +0200
committerAndreas Schwab <schwab@suse.de>2018-05-23 09:50:57 +0200
commit9aaaab7c6e4176e61c59b0a63c6ba906d875dc0e (patch)
tree8ce316f806948a2b6f3c29335d39e861dc91df84
parent8f145c77123a565b816f918969e0e35ee5b89153 (diff)
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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.
-rw-r--r--ChangeLog9
-rw-r--r--string/test-mempcpy.c1
-rw-r--r--sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S5
3 files changed, 13 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 252b0993dc..8032adfca4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -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.
diff --git a/string/test-mempcpy.c b/string/test-mempcpy.c
index c08fba895e..d98ecdd2d9 100644
--- a/string/test-mempcpy.c
+++ b/string/test-mempcpy.c
@@ -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"
diff --git a/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S b/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S
index 23c0f7a9ed..effc3ac2de 100644
--- a/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S
+++ b/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S
@@ -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):