releases/3.0.46/xfrm_user-fix-info-leak-in-copy_to_user_tmpl.patch

From d69e52e3a58dc5f29bcbe7a4e9d040044ea7b53b Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli@googlemail.com>
Date: Wed, 19 Sep 2012 11:33:41 +0000
Subject: xfrm_user: fix info leak in copy_to_user_tmpl()


From: Mathias Krause <minipli@googlemail.com>

[ Upstream commit 1f86840f897717f86d523a13e99a447e6a5d2fa5 ]

The memory used for the template copy is a local stack variable. As
struct xfrm_user_tmpl contains multiple holes added by the compiler for
alignment, not initializing the memory will lead to leaking stack bytes
to userland. Add an explicit memset(0) to avoid the info leak.

Initial version of the patch by Brad Spengler.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Brad Spengler <spender@grsecurity.net>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/xfrm/xfrm_user.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1405,6 +1405,7 @@ static int copy_to_user_tmpl(struct xfrm
 		struct xfrm_user_tmpl *up = &vec[i];
 		struct xfrm_tmpl *kp = &xp->xfrm_vec[i];
 
+		memset(up, 0, sizeof(*up));
 		memcpy(&up->id, &kp->id, sizeof(up->id));
 		up->family = kp->encap_family;
 		memcpy(&up->saddr, &kp->saddr, sizeof(up->saddr));