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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2007-11-02 22:53:44 +0100 |
|---|---|---|
| committer | Adrian Bunk <bunk@kernel.org> | 2007-11-02 22:53:44 +0100 |
| commit | 4c94bf7f6f414af1ac449d3d6741522311b1fc07 (patch) | |
| tree | 763a98821515ea22205a5944e816821f8bc3c7f9 | |
| parent | 2ba6064c00a38885e8997059908f9aed5299e196 (diff) | |
| download | linux-stable-4c94bf7f6f414af1ac449d3d6741522311b1fc07.tar.gz linux-stable-4c94bf7f6f414af1ac449d3d6741522311b1fc07.tar.bz2 linux-stable-4c94bf7f6f414af1ac449d3d6741522311b1fc07.zip | |
[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>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
| -rw-r--r-- | net/802/psnap.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/net/802/psnap.c b/net/802/psnap.c index 34e42968b477..b920aa206666 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->h.raw); if (proto) { @@ -64,14 +67,18 @@ static int snap_rcv(struct sk_buff *skb, struct net_device *dev, skb_pull(skb, 5); skb_postpull_rcsum(skb, hdr, 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; } /* |