xfrm_user: fix info leak in xfrm_notify_sa()

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 whole struct before filling
it.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Fixes: 0603eac0d6b7 ("[IPSEC]: Add XFRMA_SA/XFRMA_POLICY for delete notification")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 3259555ae7d708506a3d2a2d6d8e57b19df8d7e7..c33516ef52f25b391034fcc6d3ce7ea83dbef21c 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2715,6 +2715,7 @@ static int xfrm_notify_sa(struct xfrm_state *x, const struct km_event *c)
                struct nlattr *attr;
 
                id = nlmsg_data(nlh);
+               memset(id, 0, sizeof(*id));
                memcpy(&id->daddr, &x->id.daddr, sizeof(id->daddr));
                id->spi = x->id.spi;
                id->family = x->props.family;