[SRU] [Bionic/OEM-A] [PATCH 2/2] net: aquantia: oops when shutdown on already stopped device

[Kai-Heng Feng]

From: Igor Russkikh <igor.russkikh at aquantia.com>

BugLink: https://bugs.launchpad.net/bugs/1767088

In case netdev is closed at the moment of pci shutdown, aq_nic_stop
gets called second time. napi_disable in that case hangs indefinitely.
In other case, if device was never opened at all, we get oops because
of null pointer access.

We should invoke aq_nic_stop conditionally, only if device is running
at the moment of shutdown.

Reported-by: David Arcari <darcari at redhat.com>
Fixes: 90869ddfefeb ("net: aquantia: Implement pci shutdown callback")
Signed-off-by: Igor Russkikh <igor.russkikh at aquantia.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit 9a11aff25fd43d5bd2660ababdc9f564b0ba183a)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/net/ethernet/aquantia/atlantic/aq_nic.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_nic.c b/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
index c96a92118b8b..32f6d2e24d66 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
@@ -951,9 +951,11 @@ void aq_nic_shutdown(struct aq_nic_s *self)
 
 	netif_device_detach(self->ndev);
 
-	err = aq_nic_stop(self);
-	if (err < 0)
-		goto err_exit;
+	if (netif_running(self->ndev)) {
+		err = aq_nic_stop(self);
+		if (err < 0)
+			goto err_exit;
+	}
 	aq_nic_deinit(self);
 
 err_exit:
-- 
2.17.0