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GNU C Library master sources branch release/2.26/master updated. glibc-2.26-206-g04e767b
- From: hjl at sourceware dot org
- To: glibc-cvs at sourceware dot org
- Date: 4 Feb 2019 18:59:26 -0000
- Subject: GNU C Library master sources branch release/2.26/master updated. glibc-2.26-206-g04e767b
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http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=04e767b59b16befce93c6086362acbc1fae63f4e
commit 04e767b59b16befce93c6086362acbc1fae63f4e
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Mon Feb 4 08:55:52 2019 -0800
x86-64 memcmp: Use unsigned Jcc instructions on size [BZ #24155]
Since the size argument is unsigned. we should use unsigned Jcc
instructions, instead of signed, to check size.
Tested on x86-64 and x32, with and without --disable-multi-arch.
[BZ #24155]
CVE-2019-7309
* NEWS: Updated for CVE-2019-7309.
* sysdeps/x86_64/memcmp.S: Use RDX_LP for size. Clear the
upper 32 bits of RDX register for x32. Use unsigned Jcc
instructions, instead of signed.
* sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memcmp-2.
* sysdeps/x86_64/x32/tst-size_t-memcmp-2.c: New test.
(cherry picked from commit 3f635fb43389b54f682fc9ed2acc0b2aaf4a923d)
diff --git a/ChangeLog b/ChangeLog
index bc1f461..6570bc6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2019-02-04 H.J. Lu <hongjiu.lu@intel.com>
+
+ [BZ #24155]
+ CVE-2019-7309
+ * NEWS: Updated for CVE-2019-7309.
+ * sysdeps/x86_64/memcmp.S: Use RDX_LP for size. Clear the
+ upper 32 bits of RDX register for x32. Use unsigned Jcc
+ instructions, instead of signed.
+ * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memcmp-2.
+ * sysdeps/x86_64/x32/tst-size_t-memcmp-2.c: New test.
+
2019-02-01 H.J. Lu <hongjiu.lu@intel.com>
[BZ #24097]
diff --git a/NEWS b/NEWS
index 1bea44c..735c578 100644
--- a/NEWS
+++ b/NEWS
@@ -92,6 +92,14 @@ Security related changes:
in the assembly string/memory functions would cause a buffer overflow.
Reported by H.J. Lu.
+ CVE-2019-7309: x86-64 memcmp used signed Jcc instructions to check
+ size. For x86-64, memcmp on an object size larger than SSIZE_MAX
+ has undefined behavior. On x32, the size_t argument may be passed
+ in the lower 32 bits of the 64-bit RDX register with non-zero upper
+ 32 bits. When it happened with the sign bit of RDX register set,
+ memcmp gave the wrong result since it treated the size argument as
+ zero. Reported by H.J. Lu.
+
The following bugs are resolved with this release:
[16750] ldd: Never run file directly.
@@ -172,6 +180,8 @@ The following bugs are resolved with this release:
[24018] gettext may return NULL
[24027] malloc: Integer overflow in realloc
[24097] Can't use 64-bit register for size_t in assembly codes for x32 (CVE-2019-6488)
+ [24155] x32 memcmp can treat positive length as 0 (if sign bit in RDX is set) (CVE-2019-7309)
+
Version 2.26
diff --git a/sysdeps/x86_64/memcmp.S b/sysdeps/x86_64/memcmp.S
index 0828a22..9ae9066 100644
--- a/sysdeps/x86_64/memcmp.S
+++ b/sysdeps/x86_64/memcmp.S
@@ -21,14 +21,18 @@
.text
ENTRY (memcmp)
- test %rdx, %rdx
+#ifdef __ILP32__
+ /* Clear the upper 32 bits. */
+ movl %edx, %edx
+#endif
+ test %RDX_LP, %RDX_LP
jz L(finz)
cmpq $1, %rdx
- jle L(finr1b)
+ jbe L(finr1b)
subq %rdi, %rsi
movq %rdx, %r10
cmpq $32, %r10
- jge L(gt32)
+ jae L(gt32)
/* Handle small chunks and last block of less than 32 bytes. */
L(small):
testq $1, %r10
@@ -156,7 +160,7 @@ L(A32):
movq %r11, %r10
andq $-32, %r10
cmpq %r10, %rdi
- jge L(mt16)
+ jae L(mt16)
/* Pre-unroll to be ready for unrolled 64B loop. */
testq $32, %rdi
jz L(A64)
@@ -178,7 +182,7 @@ L(A64):
movq %r11, %r10
andq $-64, %r10
cmpq %r10, %rdi
- jge L(mt32)
+ jae L(mt32)
L(A64main):
movdqu (%rdi,%rsi), %xmm0
@@ -216,7 +220,7 @@ L(mt32):
movq %r11, %r10
andq $-32, %r10
cmpq %r10, %rdi
- jge L(mt16)
+ jae L(mt16)
L(A32main):
movdqu (%rdi,%rsi), %xmm0
@@ -254,7 +258,7 @@ L(ATR):
movq %r11, %r10
andq $-32, %r10
cmpq %r10, %rdi
- jge L(mt16)
+ jae L(mt16)
testq $16, %rdi
jz L(ATR32)
@@ -325,7 +329,7 @@ L(ATR64main):
movq %r11, %r10
andq $-32, %r10
cmpq %r10, %rdi
- jge L(mt16)
+ jae L(mt16)
L(ATR32res):
movdqa (%rdi,%rsi), %xmm0
diff --git a/sysdeps/x86_64/x32/Makefile b/sysdeps/x86_64/x32/Makefile
index 1557724..8748956 100644
--- a/sysdeps/x86_64/x32/Makefile
+++ b/sysdeps/x86_64/x32/Makefile
@@ -8,7 +8,8 @@ endif
ifeq ($(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-strnlen
+ tst-size_t-strncmp tst-size_t-strncpy tst-size_t-strnlen \
+ tst-size_t-memcmp-2
endif
ifeq ($(subdir),wcsmbs)
diff --git a/sysdeps/x86_64/x32/tst-size_t-memcmp-2.c b/sysdeps/x86_64/x32/tst-size_t-memcmp-2.c
new file mode 100644
index 0000000..d8ae1a0
--- /dev/null
+++ b/sysdeps/x86_64/x32/tst-size_t-memcmp-2.c
@@ -0,0 +1,79 @@
+/* Test memcmp 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 TEST_MAIN
+#ifdef WIDE
+# define TEST_NAME "wmemcmp"
+#else
+# define TEST_NAME "memcmp"
+#endif
+
+#include "test-size_t.h"
+
+#ifdef WIDE
+# include <inttypes.h>
+# include <wchar.h>
+
+# define MEMCMP wmemcmp
+# define CHAR wchar_t
+#else
+# define MEMCMP memcmp
+# define CHAR char
+#endif
+
+IMPL (MEMCMP, 1)
+
+typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
+
+static int
+__attribute__ ((noinline, noclone))
+do_memcmp (parameter_t a, parameter_t b)
+{
+ return CALL (&b, a.p, b.p, a.len);
+}
+
+static int
+test_main (void)
+{
+ test_init ();
+
+ parameter_t dest = { { page_size / sizeof (CHAR) }, buf1 };
+ parameter_t src = { { 0 }, buf2 };
+
+ memcpy (buf1, buf2, page_size);
+
+ CHAR *p = (CHAR *) buf1;
+ p[page_size / sizeof (CHAR) - 1] = (CHAR) 1;
+
+ int ret = 0;
+ FOR_EACH_IMPL (impl, 0)
+ {
+ src.fn = impl->fn;
+ int res = do_memcmp (dest, src);
+ if (res >= 0)
+ {
+ error (0, 0, "Wrong result in function %s: %i >= 0",
+ impl->name, res);
+ ret = 1;
+ }
+ }
+
+ return ret ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+
+#include <support/test-driver.c>
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 11 +++++++++++
NEWS | 10 ++++++++++
sysdeps/x86_64/memcmp.S | 20 ++++++++++++--------
sysdeps/x86_64/x32/Makefile | 3 ++-
.../{tst-size_t-memcmp.c => tst-size_t-memcmp-2.c} | 7 +++++--
5 files changed, 40 insertions(+), 11 deletions(-)
copy sysdeps/x86_64/x32/{tst-size_t-memcmp.c => tst-size_t-memcmp-2.c} (92%)
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