From d01dbeb6af7a0848063033f73c3d146fec7451f3 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 30 Sep 2008 02:03:19 -0700 Subject: 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: Herbert Xu Signed-off-by: David S. Miller --- net/xfrm/xfrm_output.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c index ac25b4c0e982..dc50f1e71f76 100644 --- a/net/xfrm/xfrm_output.c +++ b/net/xfrm/xfrm_output.c @@ -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); - - return 0; + 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) -- cgit v1.2.2