[PATCH 4.18 155/158] RDMA/cma: Do not ignore net namespace for unbound cm_id

[Greg Kroah-Hartman]

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

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

From: Parav Pandit <parav@xxxxxxxxxxxx>

[ Upstream commit 643d213a9a034fa04f5575a40dfc8548e33ce04f ]

Currently if the cm_id is not bound to any netdevice, than for such cm_id,
net namespace is ignored; which is incorrect.

Regardless of cm_id bound to a netdevice or not, net namespace must
match. When a cm_id is bound to a netdevice, in such case net namespace
and netdevice both must match.

Fixes: 4c21b5bcef73 ("IB/cma: Add net_dev and private data checks to RDMA CM")
Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
Reviewed-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
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 |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -1445,9 +1445,16 @@ static bool cma_match_net_dev(const stru
 		       (addr->src_addr.ss_family == AF_IB ||
 			rdma_protocol_roce(id->device, port_num));
 
-	return !addr->dev_addr.bound_dev_if ||
-	       (net_eq(dev_net(net_dev), addr->dev_addr.net) &&
-		addr->dev_addr.bound_dev_if == net_dev->ifindex);
+	/*
+	 * Net namespaces must match, and if the listner is listening
+	 * on a specific netdevice than netdevice must match as well.
+	 */
+	if (net_eq(dev_net(net_dev), addr->dev_addr.net) &&
+	    (!!addr->dev_addr.bound_dev_if ==
+	     (addr->dev_addr.bound_dev_if == net_dev->ifindex)))
+		return true;
+	else
+		return false;
 }
 
 static struct rdma_id_private *cma_find_listener(