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authorHerbert Xu <herbert@gondor.apana.org.au>2007-08-21 00:06:37 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-08-21 20:58:13 -0700
commitd92a7db710c32db826a00ba9bc7a22e741d5041e (patch)
tree800eeede84fea9ab9397b7a1a326629cf3c45bc8 /net/802
parent39dad26c37fdb1382e4173172a2704fa278f7fd6 (diff)
downloadlinux-2.6.34-ux500-d92a7db710c32db826a00ba9bc7a22e741d5041e.tar.gz
[SNAP]: Check packet length before reading
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 <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/802')
-rw-r--r--net/802/psnap.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/net/802/psnap.c b/net/802/psnap.c
index 04ee43e7538..31128cb92a2 100644
--- a/net/802/psnap.c
+++ b/net/802/psnap.c
@@ -55,6 +55,9 @@ static int snap_rcv(struct sk_buff *skb, struct net_device *dev,
.type = __constant_htons(ETH_P_SNAP),
};
+ if (unlikely(!pskb_may_pull(skb, 5)))
+ goto drop;
+
rcu_read_lock();
proto = find_snap_client(skb_transport_header(skb));
if (proto) {
@@ -62,14 +65,18 @@ static int snap_rcv(struct sk_buff *skb, struct net_device *dev,
skb->transport_header += 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;
}
/*