Commit 3f32d0be authored Sep 25, 2018 by Parthasarathy Bhuvaragan Committed by David S. Miller Sep 25, 2018

tipc: lock wakeup & inputq at tipc_link_reset()



In tipc_link_reset() we copy the wakeup queue to input queue using
skb_queue_splice_init(link->wakeupq, link->inputq).
This is performed without holding any locks. The lists might be
simultaneously be accessed by other cpu threads in tipc_sk_rcv(),
something leading to to random missing packets.

Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 94b6ddce

net/tipc/link.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -841,9 +841,14 @@ void tipc_link_reset(struct tipc_link *l)
		l->in_session = false;
		l->session++;
		l->mtu = l->advertised_mtu;
		spin_lock_bh(&l->wakeupq.lock);
		spin_lock_bh(&l->inputq->lock);
		skb_queue_splice_init(&l->wakeupq, l->inputq);
		spin_unlock_bh(&l->inputq->lock);
		spin_unlock_bh(&l->wakeupq.lock);

		__skb_queue_purge(&l->transmq);
		__skb_queue_purge(&l->deferdq);
		skb_queue_splice_init(&l->wakeupq, l->inputq);
		__skb_queue_purge(&l->backlogq);
		l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
		l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;