Commit e3e5fc16 authored Aug 26, 2017 by Mathias Krause Committed by Steffen Klassert Aug 28, 2017

xfrm_user: fix info leak in build_expire()



The memory reserved to dump the expired xfrm state includes padding
bytes in struct xfrm_user_expire added by the compiler for alignment. To
prevent the heap info leak, memset(0) the remainder of the struct.
Initializing the whole structure isn't needed as copy_to_user_state()
already takes care of clearing the padding bytes within the 'state'
member.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

parent 50329c8a

net/xfrm/xfrm_user.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -2578,6 +2578,8 @@ static int build_expire(struct sk_buff skb, struct xfrm_state x, const struct
		ue = nlmsg_data(nlh);
		copy_to_user_state(x, &ue->state);
		ue->hard = (c->data.hard != 0) ? 1 : 0;
		/* clear the padding bytes */
		memset(&ue->hard + 1, 0, sizeof(ue) - offsetofend(typeof(ue), hard));

		err = xfrm_mark_put(skb, &x->mark);
		if (err)

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