[PATCH 4.16 160/272] IB/core: Honor port_num while resolving GID for IB link layer

[Greg Kroah-Hartman]

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

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

From: Parav Pandit <parav@xxxxxxxxxxxx>

[ Upstream commit 563c4ba3bd2b8b0b21c65669ec2226b1cfa1138b ]

ah_attr contains the port number to which cm_id is bound. However, while
searching for GID table for matching GID entry, the port number is
ignored.

This could cause the wrong GID to be used when the ah_attr is converted to
an AH.

Reviewed-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/infiniband/core/multicast.c |   24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

--- a/drivers/infiniband/core/multicast.c
+++ b/drivers/infiniband/core/multicast.c
@@ -724,21 +724,19 @@ int ib_init_ah_from_mcmember(struct ib_d
 {
 	int ret;
 	u16 gid_index;
-	u8 p;
 
-	if (rdma_protocol_roce(device, port_num)) {
-		ret = ib_find_cached_gid_by_port(device, &rec->port_gid,
-						 gid_type, port_num,
-						 ndev,
-						 &gid_index);
-	} else if (rdma_protocol_ib(device, port_num)) {
-		ret = ib_find_cached_gid(device, &rec->port_gid,
-					 IB_GID_TYPE_IB, NULL, &p,
-					 &gid_index);
-	} else {
-		ret = -EINVAL;
-	}
+	/* GID table is not based on the netdevice for IB link layer,
+	 * so ignore ndev during search.
+	 */
+	if (rdma_protocol_ib(device, port_num))
+		ndev = NULL;
+	else if (!rdma_protocol_roce(device, port_num))
+		return -EINVAL;
 
+	ret = ib_find_cached_gid_by_port(device, &rec->port_gid,
+					 gid_type, port_num,
+					 ndev,
+					 &gid_index);
 	if (ret)
 		return ret;