[PATCH net v2] net: Avoid calling WARN_ON() on -ENOMEM in netif_change_net_namespace()

[Ivan Abramov]

It's pointless to call WARN_ON() in case of an allocation failure in
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: 8b41d1887db7 ("[NET]: Fix running without sysfs")
Reported-by: syzbot+1df6ffa7a6274ae264db@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://lore.kernel.org/netdev/000000000000a45a92061ce6cc7d@xxxxxxxxxx/
Link: https://lore.kernel.org/netdev/20250328011302.743860-1-i.abramov@xxxxxxxxxxxxxxxxx/
Signed-off-by: Ivan Abramov <i.abramov@xxxxxxxxxxxxxxxxx>
---
v2: Add Reported-by and Closes tags and make sure to commit against
latest netdev/net as per Kuniyuki Iwashima's observation. Also add Link 
tag.

 net/core/dev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index be17e0660144..001c362a4c1d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -12196,7 +12196,7 @@ int netif_change_net_namespace(struct net_device *dev, struct net *net,
 	dev_set_uevent_suppress(&dev->dev, 1);
 	err = device_rename(&dev->dev, dev->name);
 	dev_set_uevent_suppress(&dev->dev, 0);
-	WARN_ON(err);
+	WARN_ON(err && err != -ENOMEM);
 
 	/* Send a netdev-add uevent to the new namespace */
 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
-- 
2.39.5