The snap_rcv code reads 5 bytes so we should make sure that we have 5 bytes in the head before proceeding. Based on diagnosis and fix by Evgeniy Polyakov, reported by Alan J. Wylie. Patch also kills the skb->sk assignment before kfree_skb since it's redundant. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/802/psnap.c | 17 ++++++++++++----- 1 files changed, 12 insertions(+), 5 deletions(-) Index: 2.6/net/802/psnap.c =================================================================== --- 2.6.orig/net/802/psnap.c +++ 2.6/net/802/psnap.c @@ -55,6 +55,9 @@ static int snap_rcv(struct sk_buff *skb, .type = __constant_htons(ETH_P_SNAP), }; + if (unlikely(!pskb_may_pull(skb, 5))) + goto drop; + rcu_read_lock(); proto = find_snap_client(skb->h.raw); if (proto) { @@ -62,14 +65,18 @@ static int snap_rcv(struct sk_buff *skb, skb->h.raw += 5; skb_pull_rcsum(skb, 5); rc = proto->rcvfunc(skb, dev, &snap_packet_type, orig_dev); - } else { - skb->sk = NULL; - kfree_skb(skb); - rc = 1; } - rcu_read_unlock(); + + if (unlikely(!proto)) + goto drop; + +out: return rc; + +drop: + kfree_skb(skb); + goto out; } /* -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/