[PATCH 3.16 152/294] xfrm_user: fix info leak in build_aevent()

[Ben Hutchings]

3.16.50-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Mathias Krause <mini...@googlemail.com>

commit 931e79d7a7ddee4709c56b39de169a36804589a1 upstream.

The memory reserved to dump the ID of the xfrm state includes a padding
byte in struct xfrm_usersa_id added by the compiler for alignment. To
prevent the heap info leak, memset(0) the sa_id before filling it.

Cc: Jamal Hadi Salim <j...@mojatatu.com>
Fixes: d51d081d6504 ("[IPSEC]: Sync series - user")
Signed-off-by: Mathias Krause <mini...@googlemail.com>
Signed-off-by: Steffen Klassert <steffen.klass...@secunet.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 net/xfrm/xfrm_user.c | 1 +
 1 file changed, 1 insertion(+)

--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1752,6 +1752,7 @@ static int build_aevent(struct sk_buff *
                return -EMSGSIZE;
 
        id = nlmsg_data(nlh);
+       memset(&id->sa_id, 0, sizeof(id->sa_id));
        memcpy(&id->sa_id.daddr, &x->id.daddr, sizeof(x->id.daddr));
        id->sa_id.spi = x->id.spi;
        id->sa_id.family = x->props.family;