Commit 7bf66305 authored Sep 05, 2013 by Jason Wang Committed by David S. Miller Sep 05, 2013

tuntap: orphan frags before trying to set tx timestamp



sock_tx_timestamp() will clear all zerocopy flags of skb which may lead the
frags never to be orphaned. This will break guest to guest traffic when zerocopy
is enabled. Fix this by orphaning the frags before trying to set tx time stamp.

The issue were introduced by commit eda29772
(tun: Support software transmit time stamping).

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 4bfb0513

drivers/net/tun.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -749,15 +749,17 @@ static netdev_tx_t tun_net_xmit(struct sk_buff skb, struct net_device dev)
		>= dev->tx_queue_len / tun->numqueues)
		goto drop;

		if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
		goto drop;

		if (skb->sk) {
		sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
		sw_tx_timestamp(skb);
		}

		/* Orphan the skb - required as we might hang on to it
		* for indefinite time. */
		if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
		goto drop;
		* for indefinite time.
		*/
		skb_orphan(skb);

		nf_reset(skb);

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