xfrm_user: fix info leak in copy_to_user_state()

[ Upstream commit f778a636713a435d3a922c60b1622a91136560c1 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index d78ebe20df725ae7c0cb663c2da1770b3fe184bb..8e878ebf49a58d74c3cebd9362b818307932a458 100644 (file)
--- 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));