net: ena: fix NULL dereference due to untimely napi initialization

napi poll functions should be initialized before running request_irq(),
to handle a rare condition where there is a pending interrupt, causing
the ISR to fire immediately while the poll function wasn't set yet,
causing a NULL dereference.

Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index ce18e07ff5ad..d906293ce07d 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1575,8 +1575,6 @@ static int ena_up_complete(struct ena_adapter *adapter)
         if (rc)
                 return rc;
 
-        ena_init_napi(adapter);
-
         ena_change_mtu(adapter->netdev, adapter->netdev->mtu);
 
         ena_refill_all_rx_bufs(adapter);
@@ -1730,6 +1728,13 @@ static int ena_up(struct ena_adapter *adapter)
 
         ena_setup_io_intr(adapter);
 
+        /* napi poll functions should be initialized before running
+         * request_irq(), to handle a rare condition where there is a pending
+         * interrupt, causing the ISR to fire immediately while the poll
+         * function wasn't set yet, causing a null dereference
+         */
+        ena_init_napi(adapter);
+
         rc = ena_request_io_irq(adapter);
         if (rc)
                 goto err_req_irq;