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[Lucid,CVE,1/3] xfrm_user: fix info leak in copy_to_user_tmpl()

Message ID 1363950765-9771-2-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques March 22, 2013, 11:12 a.m. UTC 
From: Mathias Krause <minipli@googlemail.com>

CVE-2012-6537

BugLink: http://bugs.launchpad.net/bugs/1156716

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.

Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 1f86840f897717f86d523a13e99a447e6a5d2fa5)

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 net/xfrm/xfrm_user.c | 1 +
 1 file changed, 1 insertion(+)
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Patch

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index b95a2d6..ab5f23c 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1176,6 +1176,7 @@  static int copy_to_user_tmpl(struct xfrm_policy *xp, struct sk_buff *skb)
 		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));