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| author | Al Viro <viro@ZenIV.linux.org.uk> | 2016-09-15 02:35:29 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-09-15 12:54:04 -0700 |
| commit | 1c109fabbd51863475cd12ac206bdd249aee35af (patch) | |
| tree | 2b4a8204e47e27945a8ec57c4abe146ece8fe1e1 | |
| parent | 4cea8776571b18db7485930cb422faa739580c8c (diff) | |
| download | linux-1c109fabbd51863475cd12ac206bdd249aee35af.tar.gz linux-1c109fabbd51863475cd12ac206bdd249aee35af.tar.bz2 linux-1c109fabbd51863475cd12ac206bdd249aee35af.zip | |
fix minor infoleak in get_user_ex()
get_user_ex(x, ptr) should zero x on failure. It's not a lot of a leak
(at most we are leaking uninitialized 64bit value off the kernel stack,
and in a fairly constrained situation, at that), but the fix is trivial,
so...
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[ This sat in different branch from the uaccess fixes since mid-August ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index e3af86f58eaf..2131c4ce7d8a 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -433,7 +433,11 @@ do { \ #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ asm volatile("1: mov"itype" %1,%"rtype"0\n" \ "2:\n" \ - _ASM_EXTABLE_EX(1b, 2b) \ + ".section .fixup,\"ax\"\n" \ + "3:xor"itype" %"rtype"0,%"rtype"0\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE_EX(1b, 3b) \ : ltype(x) : "m" (__m(addr))) #define __put_user_nocheck(x, ptr, size) \ |