[PATCH net v4 3/4] octeon_ep_vf: fix race conditions in ndo_get_stats64

[Shinas Rasheed]

ndo_get_stats64() can race with ndo_stop(), which frees input and
output queue resources. Check if netdev is running before accessing
per queue resources.

Fixes: c3fad23cdc06 ("octeon_ep_vf: add support for ndo ops")
Signed-off-by: Shinas Rasheed <srasheed@xxxxxxxxxxx>
---
V4:
  - Check if netdev is running, as decision for accessing resources
    rather than availing lock implementations, in ndo_get_stats64()

V3: https://lore.kernel.org/all/20241218115111.2407958-4-srasheed@xxxxxxxxxxx/
  - No changes

V2: https://lore.kernel.org/all/20241216075842.2394606-4-srasheed@xxxxxxxxxxx/
  - Changed sync mechanism to fix race conditions from using an atomic
    set_bit ops to a much simpler synchronize_net()

V1: https://lore.kernel.org/all/20241203072130.2316913-4-srasheed@xxxxxxxxxxx/

 drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c
index 7e6771c9cdbb..9b29cd698361 100644
--- a/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c
@@ -786,6 +786,10 @@ static void octep_vf_get_stats64(struct net_device *netdev,
 	tx_bytes = 0;
 	rx_packets = 0;
 	rx_bytes = 0;
+
+	if (!netif_running(netdev))
+		return;
+
 	for (q = 0; q < oct->num_oqs; q++) {
 		struct octep_vf_iq *iq = oct->iq[q];
 		struct octep_vf_oq *oq = oct->oq[q];
-- 
2.25.1