Commit 21962692 authored Mar 05, 2014 by Eric Dumazet Committed by David S. Miller Mar 07, 2014

tcp: do not leak non zero tstamp in output packets



Usage of skb->tstamp should remain private to TCP stack
(only set on packets on write queue, not on cloned ones)

Otherwise, packets given to loopback interface with a non null tstamp
can confuse netif_rx() / net_timestamp_check()

Other possibility would be to clear tstamp in loopback_xmit(),
as done in skb_scrub_packet()

Fixes: 740b0f18 ("tcp: switch rtt estimations to usec resolution")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 28f084cc

net/ipv4/tcp_output.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -882,6 +882,8 @@ static int tcp_transmit_skb(struct sock sk, struct sk_buff skb, int clone_it,
	skb = skb_clone(skb, gfp_mask);		skb = skb_clone(skb, gfp_mask);
	if (unlikely(!skb))		if (unlikely(!skb))
	return -ENOBUFS;		return -ENOBUFS;
			/* Our usage of tstamp should remain private */
			skb->tstamp.tv64 = 0;
	}		}

	inet = inet_sk(sk);		inet = inet_sk(sk);