4.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Al Viro <v...@zeniv.linux.org.uk>

commit 1c109fabbd51863475cd12ac206bdd249aee35af upstream.

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...

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
[ This sat in different branch from the uaccess fixes since mid-August ]
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/x86/include/asm/uaccess.h |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -414,7 +414,11 @@ 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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