From: Michal Swiatkowski <michal.swiatkowski@intel.com>
Date: Wed, 9 Oct 2019 07:09:47 -0700
Subject: ice: Check for null pointer dereference when setting rings
Patch-mainline: v5.5-rc1
Git-commit: eb0ee8abfeb9ff4b98e8e40217b8667bfb08587a
References: jsc#SLE-7926

Without this check rebuild vsi can lead to kernel panic.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/ice/ice_main.c |   18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -4303,8 +4303,13 @@ int ice_vsi_setup_tx_rings(struct ice_vs
 	}
 
 	ice_for_each_txq(vsi, i) {
-		vsi->tx_rings[i]->netdev = vsi->netdev;
-		err = ice_setup_tx_ring(vsi->tx_rings[i]);
+		struct ice_ring *ring = vsi->tx_rings[i];
+
+		if (!ring)
+			return -EINVAL;
+
+		ring->netdev = vsi->netdev;
+		err = ice_setup_tx_ring(ring);
 		if (err)
 			break;
 	}
@@ -4329,8 +4334,13 @@ int ice_vsi_setup_rx_rings(struct ice_vs
 	}
 
 	ice_for_each_rxq(vsi, i) {
-		vsi->rx_rings[i]->netdev = vsi->netdev;
-		err = ice_setup_rx_ring(vsi->rx_rings[i]);
+		struct ice_ring *ring = vsi->rx_rings[i];
+
+		if (!ring)
+			return -EINVAL;
+
+		ring->netdev = vsi->netdev;
+		err = ice_setup_rx_ring(ring);
 		if (err)
 			break;
 	}