Commit 8728c544 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: dev_pick_tx() fix

When dev_pick_tx() caches tx queue_index on a socket, we must check
socket dst_entry matches skb one, or risk a crash later, as reported by
Denys Fedorysychenko, if old packets are in flight during a route
change, involving devices with different number of queues.

Bug introduced by commit a4ee3ce3

(net: Use sk_tx_queue_mapping for connected sockets)
Reported-by: default avatarDenys Fedorysychenko <>
Signed-off-by: default avatarEric Dumazet <>
Signed-off-by: default avatarDavid S. Miller <>
parent 4eaa0e3c
......@@ -1989,8 +1989,12 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev,
if (dev->real_num_tx_queues > 1)
queue_index = skb_tx_hash(dev, skb);
if (sk && sk->sk_dst_cache)
sk_tx_queue_set(sk, queue_index);
if (sk) {
struct dst_entry *dst = rcu_dereference(sk->sk_dst_cache);
if (dst && skb_dst(skb) == dst)
sk_tx_queue_set(sk, queue_index);
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