Commit d01dbeb6 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

ipsec: Fix pskb_expand_head corruption in xfrm_state_check_space 



We're never supposed to shrink the headroom or tailroom.  In fact,
shrinking the headroom is a fatal action.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 94aca1da

net/xfrm/xfrm_output.c

+8 −4
Original line number Diff line number Diff line
@@ -27,10 +27,14 @@ static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb) 
		- skb_headroom(skb);

	int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);



	if (nhead > 0 || ntail > 0)

		return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);



	if (nhead <= 0) {

		if (ntail <= 0)

			return 0;

		nhead = 0;

	} else if (ntail < 0)

		ntail = 0;



	return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);

}



static int xfrm_output_one(struct sk_buff *skb, int err)