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[PATCH 5/8] x86-64 memset/wmemset: Properly handle the length parameter [BZ# 24097]
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: libc-alpha at sourceware dot org
- Date: Fri, 18 Jan 2019 12:12:34 -0800
- Subject: [PATCH 5/8] x86-64 memset/wmemset: Properly handle the length parameter [BZ# 24097]
- References: <20190118201237.6729-1-hjl.tools@gmail.com>
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 memset/wmemset 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/memset-avx512-no-vzeroupper.S: Use
RDX_LP for length. Clear the upper 32 bits of RDX register.
* sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: Likewise.
* sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-wmemset.
* sysdeps/x86_64/x32/tst-size_t-memset.c: New file.
* sysdeps/x86_64/x32/tst-size_t-wmemset.c: Likewise.
---
.../multiarch/memset-avx512-no-vzeroupper.S | 6 +-
.../multiarch/memset-vec-unaligned-erms.S | 34 +++++----
sysdeps/x86_64/x32/Makefile | 4 +-
sysdeps/x86_64/x32/tst-size_t-memset.c | 73 +++++++++++++++++++
sysdeps/x86_64/x32/tst-size_t-wmemset.c | 20 +++++
5 files changed, 121 insertions(+), 16 deletions(-)
create mode 100644 sysdeps/x86_64/x32/tst-size_t-memset.c
create mode 100644 sysdeps/x86_64/x32/tst-size_t-wmemset.c
diff --git a/sysdeps/x86_64/multiarch/memset-avx512-no-vzeroupper.S b/sysdeps/x86_64/multiarch/memset-avx512-no-vzeroupper.S
index 6506ce6252..cd7a32c7c2 100644
--- a/sysdeps/x86_64/multiarch/memset-avx512-no-vzeroupper.S
+++ b/sysdeps/x86_64/multiarch/memset-avx512-no-vzeroupper.S
@@ -29,12 +29,16 @@
.section .text.avx512,"ax",@progbits
#if defined PIC
ENTRY (MEMSET_CHK)
- cmpq %rdx, %rcx
+ cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET (__chk_fail)
END (MEMSET_CHK)
#endif
ENTRY (MEMSET)
+# ifdef __ILP32__
+ /* Clear the upper 32 bits. */
+ mov %edx, %edx
+# endif
vpxor %xmm0, %xmm0, %xmm0
vmovd %esi, %xmm1
lea (%rdi, %rdx), %rsi
diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
index 71a0887c68..5e0d307d85 100644
--- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
@@ -75,8 +75,8 @@
.section SECTION(.text),"ax",@progbits
#if VEC_SIZE == 16 && IS_IN (libc)
ENTRY (__bzero)
- movq %rdi, %rax /* Set return value. */
- movq %rsi, %rdx /* Set n. */
+ mov %RDI_LP, %RAX_LP /* Set return value. */
+ mov %RSI_LP, %RDX_LP /* Set n. */
pxor %xmm0, %xmm0
jmp L(entry_from_bzero)
END (__bzero)
@@ -86,13 +86,13 @@ weak_alias (__bzero, bzero)
#if IS_IN (libc)
# if defined SHARED
ENTRY_CHK (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned))
- cmpq %rdx, %rcx
+ cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET (__chk_fail)
END_CHK (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned))
# endif
ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))
- shlq $2, %rdx
+ shl $2, %RDX_LP
WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
jmp L(entry_from_bzero)
END (WMEMSET_SYMBOL (__wmemset, unaligned))
@@ -100,13 +100,17 @@ END (WMEMSET_SYMBOL (__wmemset, unaligned))
#if defined SHARED && IS_IN (libc)
ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
- cmpq %rdx, %rcx
+ cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET (__chk_fail)
END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
#endif
ENTRY (MEMSET_SYMBOL (__memset, unaligned))
MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
+# ifdef __ILP32__
+ /* Clear the upper 32 bits. */
+ mov %edx, %edx
+# endif
L(entry_from_bzero):
cmpq $VEC_SIZE, %rdx
jb L(less_vec)
@@ -122,14 +126,14 @@ END (MEMSET_SYMBOL (__memset, unaligned))
# if VEC_SIZE == 16
ENTRY (__memset_chk_erms)
- cmpq %rdx, %rcx
+ cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET (__chk_fail)
END (__memset_chk_erms)
/* Only used to measure performance of REP STOSB. */
ENTRY (__memset_erms)
/* Skip zero length. */
- testq %rdx, %rdx
+ test %RDX_LP, %RDX_LP
jnz L(stosb)
movq %rdi, %rax
ret
@@ -141,11 +145,11 @@ ENTRY (MEMSET_SYMBOL (__memset, erms))
L(stosb):
/* Issue vzeroupper before rep stosb. */
VZEROUPPER
- movq %rdx, %rcx
+ mov %RDX_LP, %RCX_LP
movzbl %sil, %eax
- movq %rdi, %rdx
+ mov %RDI_LP, %RDX_LP
rep stosb
- movq %rdx, %rax
+ mov %RDX_LP, %RAX_LP
ret
# if VEC_SIZE == 16
END (__memset_erms)
@@ -155,16 +159,20 @@ END (MEMSET_SYMBOL (__memset, erms))
# if defined SHARED && IS_IN (libc)
ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
- cmpq %rdx, %rcx
+ cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET (__chk_fail)
END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
# endif
ENTRY (MEMSET_SYMBOL (__memset, unaligned_erms))
MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
- cmpq $VEC_SIZE, %rdx
+# ifdef __ILP32__
+ /* Clear the upper 32 bits. */
+ mov %edx, %edx
+# endif
+ cmp $VEC_SIZE, %RDX_LP
jb L(less_vec)
- cmpq $(VEC_SIZE * 2), %rdx
+ cmp $(VEC_SIZE * 2), %RDX_LP
ja L(stosb_more_2x_vec)
/* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx)
diff --git a/sysdeps/x86_64/x32/Makefile b/sysdeps/x86_64/x32/Makefile
index e99dbd7c86..98bd9ae9cd 100644
--- a/sysdeps/x86_64/x32/Makefile
+++ b/sysdeps/x86_64/x32/Makefile
@@ -7,9 +7,9 @@ endif
ifeq ($(subdir),string)
tests += tst-size_t-memchr tst-size_t-memcmp tst-size_t-memcpy \
- tst-size_t-memrchr
+ tst-size_t-memrchr tst-size_t-memset
endif
ifeq ($(subdir),wcsmbs)
-tests += tst-size_t-wmemchr tst-size_t-wmemcmp
+tests += tst-size_t-wmemchr tst-size_t-wmemcmp tst-size_t-wmemset
endif
diff --git a/sysdeps/x86_64/x32/tst-size_t-memset.c b/sysdeps/x86_64/x32/tst-size_t-memset.c
new file mode 100644
index 0000000000..2c367af6cd
--- /dev/null
+++ b/sysdeps/x86_64/x32/tst-size_t-memset.c
@@ -0,0 +1,73 @@
+/* Test memset 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 "wmemset"
+#else
+# define TEST_NAME "memset"
+#endif /* WIDE */
+
+#include "test-size_t.h"
+
+#ifdef WIDE
+# include <wchar.h>
+# define MEMSET wmemset
+# define CHAR wchar_t
+#else
+# define MEMSET memset
+# define CHAR char
+#endif /* WIDE */
+
+IMPL (MEMSET, 1)
+
+typedef CHAR *(*proto_t) (CHAR *, int, size_t);
+
+static void *
+__attribute__ ((noinline, noclone))
+do_memset (parameter_t a, parameter_t b)
+{
+ return CALL (&b, a.p, (uintptr_t) b.p, a.len);
+}
+
+static int
+test_main (void)
+{
+ test_init ();
+
+ CHAR ch = 0x23;
+ parameter_t src = { { page_size / sizeof (CHAR) }, buf2 };
+ parameter_t c = { { 0 }, (void *) (uintptr_t) ch };
+
+ int ret = 0;
+ FOR_EACH_IMPL (impl, 0)
+ {
+ c.fn = impl->fn;
+ CHAR *p = (CHAR *) do_memset (src, c);
+ size_t i;
+ for (i = 0; i < src.len; i++)
+ if (p[i] != ch)
+ {
+ error (0, 0, "Wrong result in function %s", impl->name);
+ ret = 1;
+ }
+ }
+
+ return ret ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/x86_64/x32/tst-size_t-wmemset.c b/sysdeps/x86_64/x32/tst-size_t-wmemset.c
new file mode 100644
index 0000000000..955eb488c2
--- /dev/null
+++ b/sysdeps/x86_64/x32/tst-size_t-wmemset.c
@@ -0,0 +1,20 @@
+/* Test wmemset 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-memset.c"
--
2.20.1