xfrm_user: fix info leak in copy_to_user_state()

The memory reserved to dump the xfrm state includes the padding bytes of
struct xfrm_usersa_info added by the compiler for alignment (7 for
amd64, 3 for i386). Add an explicit memset(0) before filling the buffer
to avoid the info leak.

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>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 40dd50d6c4cc..d585459dc8bb 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -689,6 +689,7 @@ out:
 
 static void copy_to_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
 {
+        memset(p, 0, sizeof(*p));
         memcpy(&p->id, &x->id, sizeof(p->id));
         memcpy(&p->sel, &x->sel, sizeof(p->sel));
         memcpy(&p->lft, &x->lft, sizeof(p->lft));