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Commit b624714b authored by Jacob Keller's avatar Jacob Keller Committed by Jeff Kirsher
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fm10k: avoid possible null pointer dereference in fm10k_update_stats 



It's currently possible for fm10k_update_stats to be called during the
window when we go down and the rings are removed. This can result in
a null pointer dereference. In fm10k_get_stats64 we work around this by
using ACCESS_ONCE and a null pointer check inside the loop. Use this
same flow in the fm10k_update_stats to avoid the potential null pointer.

Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Tested-by: default avatarKrishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 1b00c6c0

drivers/net/ethernet/intel/fm10k/fm10k_pci.c

+8 −2
Original line number Original line Diff line number Diff line
@@ -377,7 +377,10 @@ void fm10k_update_stats(struct fm10k_intfc *interface) 




	/* gather some stats to the interface struct that are per queue */

	/* gather some stats to the interface struct that are per queue */

	for (bytes = 0, pkts = 0, i = 0; i < interface->num_tx_queues; i++) {

	for (bytes = 0, pkts = 0, i = 0; i < interface->num_tx_queues; i++) {

		struct fm10k_ring *tx_ring = interface->tx_ring[i];

		struct fm10k_ring *tx_ring = READ_ONCE(interface->tx_ring[i]);



		if (!tx_ring)

			continue;





		restart_queue += tx_ring->tx_stats.restart_queue;

		restart_queue += tx_ring->tx_stats.restart_queue;

		tx_busy += tx_ring->tx_stats.tx_busy;

		tx_busy += tx_ring->tx_stats.tx_busy;
@@ -396,7 +399,10 @@ void fm10k_update_stats(struct fm10k_intfc *interface) 




	/* gather some stats to the interface struct that are per queue */

	/* gather some stats to the interface struct that are per queue */

	for (bytes = 0, pkts = 0, i = 0; i < interface->num_rx_queues; i++) {

	for (bytes = 0, pkts = 0, i = 0; i < interface->num_rx_queues; i++) {

		struct fm10k_ring *rx_ring = interface->rx_ring[i];

		struct fm10k_ring *rx_ring = READ_ONCE(interface->rx_ring[i]);



		if (!rx_ring)

			continue;





		bytes += rx_ring->stats.bytes;

		bytes += rx_ring->stats.bytes;

		pkts += rx_ring->stats.packets;

		pkts += rx_ring->stats.packets;