net: ena: don't wake up tx queue when down
There is a race condition that can occur when calling ena_down(). The ena_clean_tx_irq() - which is a part of the napi handler - function might wake up the tx queue when the queue is supposed to be down (during recovery or changing the size of the queues for example) This causes the ena_start_xmit() function to trigger and possibly try to access the destroyed queues. The race is illustrated below: Flow A: Flow B(napi handler) ena_down() netif_carrier_off() netif_tx_disable() ena_clean_tx_irq() netif_tx_wake_queue() ena_napi_disable_all() ena_destroy_all_io_queues() After these flows the tx queue is active and ena_start_xmit() accesses the destroyed queue which leads to a kernel panic. fixes: 1738cd3e (net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)) Signed-off-by: Sameeh Jubran <sameehj@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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