[PATCH 4.14 069/183] RDMA/cma: Check existence of netdevice during port validation

[Greg Kroah-Hartman]

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

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

From: Parav Pandit <parav@xxxxxxxxxxxx>


[ Upstream commit 00db63c128dd3daf38f481371976c24d32678142 ]

If valid netdevice is not found for RoCE, GID table should not be
searched with NULL netdevice.

Doing so causes the search routines to ignore the netdev argument and may
match the wrong GID table entry if the netdev is deleted.

Fixes: abae1b71dd37 ("IB/cma: cma_validate_port should verify the port and netdevice")
Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
Reviewed-by: Mark Bloch <markb@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/cma.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -624,11 +624,13 @@ static inline int cma_validate_port(stru
 	if ((dev_type != ARPHRD_INFINIBAND) && rdma_protocol_ib(device, port))
 		return ret;
 
-	if (dev_type == ARPHRD_ETHER && rdma_protocol_roce(device, port))
+	if (dev_type == ARPHRD_ETHER && rdma_protocol_roce(device, port)) {
 		ndev = dev_get_by_index(&init_net, bound_if_index);
-	else
+		if (!ndev)
+			return ret;
+	} else {
 		gid_type = IB_GID_TYPE_IB;
-
+	}
 
 	ret = ib_find_cached_gid_by_port(device, gid, gid_type, port,
 					 ndev, NULL);