IB/mlx4: Check if GRH is available before using it

commit bf08e884bfd5be068fd2ccf2bc450f085d8dd853 upstream.

Before reading GRH attributes, need to make sure AH contains GRH,
and in addition, initialize GID type.

Fixes: dbf727de7440 ('IB/core: Use GID table in AH creation and dmac resolution')
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index 69739473a39c..c22454383976 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -1765,14 +1765,14 @@ static int __mlx4_ib_modify_qp(struct ib_qp *ibqp,
                 u8 port_num = mlx4_is_bonded(to_mdev(ibqp->device)->dev) ? 1 :
                         attr_mask & IB_QP_PORT ? attr->port_num : qp->port;
                 union ib_gid gid;
-                struct ib_gid_attr gid_attr;
+                struct ib_gid_attr gid_attr = {.gid_type = IB_GID_TYPE_IB};
                 u16 vlan = 0xffff;
                 u8 smac[ETH_ALEN];
                 int status = 0;
                 int is_eth = rdma_cap_eth_ah(&dev->ib_dev, port_num) &&
                         attr->ah_attr.ah_flags & IB_AH_GRH;
 
-                if (is_eth) {
+                if (is_eth && attr->ah_attr.ah_flags & IB_AH_GRH) {
                         int index = attr->ah_attr.grh.sgid_index;
 
                         status = ib_get_cached_gid(ibqp->device, port_num,