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From: Arthur Kiyanovski <akiyano@amazon.com>
Date: Tue, 9 Oct 2018 11:21:29 +0300
Subject: net: ena: fix NULL dereference due to untimely napi initialization
Patch-mainline: v4.19-rc8
Git-commit: 78a55d05def95144ca5fa9a64c49b2a0636a9866
References: bsc#1111696 bsc#1117561

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- 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_ad
 	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 *ad
 
 	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;