[PATCH AUTOSEL 4.9 7/9] net: ena: fix NULL dereference due to untimely napi initialization
From: Sasha Levin
Date: Mon Oct 22 2018 - 06:21:53 EST
From: Arthur Kiyanovski <akiyano@xxxxxxxxxx>
[ Upstream commit 78a55d05def95144ca5fa9a64c49b2a0636a9866 ]
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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/amazon/ena/ena_netdev.c | 9 +++++++--
1 file 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 1d92e034febc..0c298878bf46 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1482,8 +1482,6 @@ 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);
@@ -1643,6 +1641,13 @@ 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;
--
2.17.1