[PATCH 2/3] ieee802154: Avoid calling WARN_ON() on -ENOMEM in cfg802154_switch_netns()

[Ivan Abramov]

It's pointless to call WARN_ON() in case of an allocation failure in
dev_change_net_namespace() and device_rename(), since it only leads to
useless splats caused by deliberate fault injections, so avoid it.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 66e5c2672cd1 ("ieee802154: add netns support")
Suggested-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: Ivan Abramov <i.abramov@xxxxxxxxxxxxxxxxx>
---
 net/ieee802154/core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index ddde594513a0..8c47957f5df7 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -228,8 +228,10 @@ int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
 			continue;
 		wpan_dev->netdev->netns_local = false;
 		err = dev_change_net_namespace(wpan_dev->netdev, net, "wpan%d");
-		if (err)
+		if (err) {
+			WARN_ON(err && err != -ENOMEM);
 			break;
+		}
 		wpan_dev->netdev->netns_local = true;
 	}
 
@@ -237,7 +239,7 @@ int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
 		goto errout;
 
 	err = device_rename(&rdev->wpan_phy.dev, dev_name(&rdev->wpan_phy.dev));
-	WARN_ON(err);
+	WARN_ON(err && err != -ENOMEM);
 
 	if (err)
 		goto errout;
@@ -258,7 +260,7 @@ int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
 		wpan_dev->netdev->netns_local = false;
 		err = dev_change_net_namespace(wpan_dev->netdev, net,
 					       "wpan%d");
-		WARN_ON(err);
+		WARN_ON(err && err != -ENOMEM);
 		wpan_dev->netdev->netns_local = true;
 	}
 
-- 
2.39.5