Commit 1f86840f authored Sep 19, 2012 by Mathias Krause Committed by David S. Miller Sep 20, 2012

xfrm_user: fix info leak in copy_to_user_tmpl()



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>

parent 7b789836

net/xfrm/xfrm_user.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1425,6 +1425,7 @@ 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));

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