Subject: net: Dequeue in dev_cpu_dead() without the lock From: Sebastian Andrzej Siewior Date: Wed Sep 16 16:15:39 2020 +0200 From: Sebastian Andrzej Siewior Upstream uses skb_dequeue() to acquire lock of `input_pkt_queue'. The reason is to synchronize against a remote CPU which still thinks that the CPU is online enqueues packets to this CPU. There are no guarantees that the packet is enqueued before the callback is run, it just hope. RT however complains about an not initialized lock because it uses another lock for `input_pkt_queue' due to the IRQ-off nature of the context. Use the unlocked dequeue version for `input_pkt_queue'. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11310,7 +11310,7 @@ static int dev_cpu_dead(unsigned int old netif_rx_ni(skb); input_queue_head_incr(oldsd); } - while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) { + while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx_ni(skb); input_queue_head_incr(oldsd); }