From 3f32d0be6c16b902b687453c962d17eea5b8ea19 Mon Sep 17 00:00:00 2001 From: Parthasarathy Bhuvaragan Date: Tue, 25 Sep 2018 22:09:10 +0200 Subject: [PATCH] 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 Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index b1f0bee54eac..26cc033ee167 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -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; -- 2.11.0