From: Shannon Nelson <snelson@pensando.io>
Date: Wed, 30 Sep 2020 10:48:28 -0700
Subject: ionic: prevent early watchdog check
Patch-mainline: v5.10-rc1
Git-commit: 0816e0c8188e7db85a7284d3f0f456947ebb049c
References: jsc#SLE-16649

In one corner case scenario, the driver device lif setup can
get delayed such that the ionic_watchdog_cb() timer goes off
before the ionic->lif is set, thus causing a NULL pointer panic.
We catch the problem by checking for a NULL lif just a little
earlier in the callback.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/pensando/ionic/ionic_dev.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
@@ -19,9 +19,12 @@ static void ionic_watchdog_cb(struct tim
 	mod_timer(&ionic->watchdog_timer,
 		  round_jiffies(jiffies + ionic->watchdog_period));
 
+	if (!ionic->lif)
+		return;
+
 	hb = ionic_heartbeat_check(ionic);
 
-	if (hb >= 0 && ionic->lif)
+	if (hb >= 0)
 		ionic_link_status_check_request(ionic->lif, false);
 }