Commit 1c109fab authored Sep 15, 2016 by Al Viro Committed by Linus Torvalds Sep 15, 2016

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>

parent 4cea8776

arch/x86/include/asm/uaccess.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -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) \