net: bridge: check the length of skb after nf_bridge_maybe_copy_header()

Since nf_bridge_maybe_copy_header() may change the length of skb,
we should check the length of skb after it to handle the ppoe skbs.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 10 deletions

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 2bd11ec6d166..ee64287f1290 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -41,17 +41,13 @@ static inline unsigned packet_length(const struct sk_buff *skb)
 
 int br_dev_queue_push_xmit(struct sk_buff *skb)
 {
-        /* drop mtu oversized packets except gso */
-        if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
+        /* ip_fragment doesn't copy the MAC header */
+        if (nf_bridge_maybe_copy_header(skb) ||
+            (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))) {
                 kfree_skb(skb);
-        else {
-                /* ip_fragment doesn't copy the MAC header */
-                if (nf_bridge_maybe_copy_header(skb))
-                        kfree_skb(skb);
-                else {
-                        skb_push(skb, ETH_HLEN);
-                        dev_queue_xmit(skb);
-                }
+        } else {
+                skb_push(skb, ETH_HLEN);
+                dev_queue_xmit(skb);
         }
 
         return 0;