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 <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index ac25b4c..dc50f1e 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -27,10 +27,14 @@
- 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 0;
+ return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
}
static int xfrm_output_one(struct sk_buff *skb, int err)