[PATCH for-3.17 1/7] IB/mlx4: Avoid null pointer dereference in mlx4_ib_scan_netdevs()

Or Gerlitz
2014-08-21T11:28:37Z

When Ethernet netdev is not present for a port (e.g. when the link
layer type of the port is InfiniBand) it's possible to dereference
a null pointer when we do netdevice scanning.

To fix that, we move a section of code that needs to run only when
netdev is present to a proper if () statement.

Fixes: ad4885d2 ('IB/mlx4: Build the port IBoE GID table properly under bonding')
Reported-by: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Moni Shoua <monis-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/hw/mlx4/main.c | 49 +++++++++++++++++++-----------------
1 files changed, 26 insertions(+), 23 deletions(-)

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index e1e558a..a6a9e57 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -1786,31 +1786,34 @@ static void mlx4_ib_scan_netdevs(struct mlx4_ib_dev *ibdev,
port_state = (netif_running(curr_netdev) && netif_carrier_ok(curr_netdev)) ?
IB_PORT_ACTIVE : IB_PORT_DOWN;
mlx4_ib_set_default_gid(ibdev, curr_netdev, port);
- } else {
- reset_gid_table(ibdev, port);
- }
- /* if using bonding/team and a slave port is down, we don't the bond IP
- * based gids in the table since flows that select port by gid may get
- * the down port.
- */
- if (curr_master && (port_state == IB_PORT_DOWN)) {
- reset_gid_table(ibdev, port);
- mlx4_ib_set_default_gid(ibdev, curr_netdev, port);
- }
- /* if bonding is used it is possible that we add it to masters
- * only after IP address is assigned to the net bonding
- * interface.
- */
- if (curr_master && (old_master != curr_master)) {
- reset_gid_table(ibdev, port);
- mlx4_ib_set_default_gid(ibdev, curr_netdev, port);
- mlx4_ib_get_dev_addr(curr_master, ibdev, port);
- }
+ /* if using bonding/team and a slave port is down, we
+ * don't the bond IP based gids in the table since
+ * flows that select port by gid may get the down port.
+ */
+ if (curr_master && (port_state == IB_PORT_DOWN)) {
+ reset_gid_table(ibdev, port);
+ mlx4_ib_set_default_gid(ibdev,
+ curr_netdev, port);
+ }
+ /* if bonding is used it is possible that we add it to
+ * masters only after IP address is assigned to the
+ * net bonding interface.
+ */
+ if (curr_master && (old_master != curr_master)) {
+ reset_gid_table(ibdev, port);
+ mlx4_ib_set_default_gid(ibdev,
+ curr_netdev, port);
+ mlx4_ib_get_dev_addr(curr_master, ibdev, port);
+ }

- if (!curr_master && (old_master != curr_master)) {
+ if (!curr_master && (old_master != curr_master)) {
+ reset_gid_table(ibdev, port);
+ mlx4_ib_set_default_gid(ibdev,
+ curr_netdev, port);
+ mlx4_ib_get_dev_addr(curr_netdev, ibdev, port);
+ }
+ } else {
reset_gid_table(ibdev, port);
- mlx4_ib_set_default_gid(ibdev, curr_netdev, port);
- mlx4_ib_get_dev_addr(curr_netdev, ibdev, port);