[PATCH 4.11 006/115] s390/qeth: avoid null pointer dereference on OSN

From: Greg Kroah-Hartman
Date: Mon Jun 05 2017 - 12:28:28 EST


4.11-stable review patch. If anyone has any objections, please let me know.

------------------

From: Julian Wiedmann <jwi@xxxxxxxxxxxxxxxxxx>


[ Upstream commit 25e2c341e7818a394da9abc403716278ee646014 ]

Access card->dev only after checking whether's its valid.

Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/s390/net/qeth_l2_main.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -1091,7 +1091,6 @@ static int qeth_l2_setup_netdev(struct q
case QETH_CARD_TYPE_OSN:
card->dev = alloc_netdev(0, "osn%d", NET_NAME_UNKNOWN,
ether_setup);
- card->dev->flags |= IFF_NOARP;
break;
default:
card->dev = alloc_etherdev(0);
@@ -1106,9 +1105,12 @@ static int qeth_l2_setup_netdev(struct q
card->dev->min_mtu = 64;
card->dev->max_mtu = ETH_MAX_MTU;
card->dev->netdev_ops = &qeth_l2_netdev_ops;
- card->dev->ethtool_ops =
- (card->info.type != QETH_CARD_TYPE_OSN) ?
- &qeth_l2_ethtool_ops : &qeth_l2_osn_ops;
+ if (card->info.type == QETH_CARD_TYPE_OSN) {
+ card->dev->ethtool_ops = &qeth_l2_osn_ops;
+ card->dev->flags |= IFF_NOARP;
+ } else {
+ card->dev->ethtool_ops = &qeth_l2_ethtool_ops;
+ }
card->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
if (card->info.type == QETH_CARD_TYPE_OSD && !card->info.guestlan) {
card->dev->hw_features = NETIF_F_SG;