[PATCH net v2] netlabel: check register_netdevice_notifier() error in netlbl_unlabel_init()

[Minhong He]

netlbl_unlabel_init() installs the unlabeled connection hash table and
registers a netdevice notifier, but ignores notifier registration errors
and always returns success.

Check the error and unwind the hash table allocation on failure.

Signed-off-by: Minhong He <heminhong at kylinos.cn>
Acked-by: Paul Moore <paul at paul-moore.com>
---
v2:
- Use rcu_assign_pointer() instead of RCU_INIT_POINTER() when clearing
  netlbl_unlhsh on notifier registration failure, as suggested by Paul Moore
v1: https://lore.kernel.org/all/20260728031043.76586-1-heminhong@kylinos.cn/

 net/netlabel/netlabel_unlabeled.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 47bae5e48db6..fe1be424601f 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1397,6 +1397,7 @@ static struct notifier_block netlbl_unlhsh_netdev_notifier = {
  */
 int __init netlbl_unlabel_init(u32 size)
 {
+	int err;
 	u32 iter;
 	struct netlbl_unlhsh_tbl *hsh_tbl;
 
@@ -1419,7 +1420,16 @@ int __init netlbl_unlabel_init(u32 size)
 	rcu_assign_pointer(netlbl_unlhsh, hsh_tbl);
 	spin_unlock(&netlbl_unlhsh_lock);
 
-	register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
+	err = register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
+	if (err) {
+		spin_lock(&netlbl_unlhsh_lock);
+		rcu_assign_pointer(netlbl_unlhsh, NULL);
+		spin_unlock(&netlbl_unlhsh_lock);
+		synchronize_rcu();
+		kfree(hsh_tbl->tbl);
+		kfree(hsh_tbl);
+		return err;
+	}
 
 	return 0;
 }
-- 
2.25.1