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authorAndreas Schwab <schwab@suse.de>2018-05-22 10:37:59 +0200
committerAurelien Jarno <aurelien@aurel32.net>2018-12-20 08:14:01 +0100
commitb501c7b09eb941dc7ff21f9939c322d2c9c32ec0 (patch)
tree79c1d5409767cf30b8800d4df1e9fb3e89c24712
parentff52a12250bd381aaef91edc0269f6e3e79d20ac (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. (cherry picked from commit 9aaaab7c6e4176e61c59b0a63c6ba906d875dc0e)
-rw-r--r--ChangeLog9
-rw-r--r--NEWS2
-rw-r--r--string/test-mempcpy.c1
-rw-r--r--sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S5
4 files changed, 15 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 699e8e510e..f650db1d59 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.
+
2018-05-09 Paul Pluzhnikov <ppluzhnikov@google.com>
[BZ #22786]
diff --git a/NEWS b/NEWS
index 0ff775e578..7e1859b78e 100644
--- a/NEWS
+++ b/NEWS
@@ -65,6 +65,8 @@ The following bugs are resolved with this release:
[22715] x86-64: Properly align La_x86_64_retval to VEC_SIZE
[22786] libc: Stack buffer overflow in realpath() if input size is close
to SSIZE_MAX (CVE-2018-11236)
+ [23196] string: __mempcpy_avx512_no_vzeroupper mishandles large copies
+ (CVE-2018-11237)
Version 2.24
diff --git a/string/test-mempcpy.c b/string/test-mempcpy.c
index f4969c24a5..d1802308a1 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 664b74de49..90ac9eaff4 100644
--- a/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S
+++ b/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S
@@ -340,6 +340,7 @@ 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
@@ -370,8 +371,8 @@ 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):