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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>
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Al Viro authored and torvalds committed Sep 15, 2016
1 parent 4cea877 commit 1c109fabbd51863475cd12ac206bdd249aee35af
Showing with 5 additions and 1 deletion.
  1. +5 −1 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) \

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