[PATCH] can: Fix error path of can_init

[YueHaibing]

This patch add error path for can_init to
avoid possible crash if some error occurs.

Fixes: 0d66548a10cb ("[CAN]: Add PF_CAN core module")
Signed-off-by: YueHaibing <yuehaib...@huawei.com>
---
 net/can/af_can.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/net/can/af_can.c b/net/can/af_can.c
index 1684ba5..a1781ea 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -958,6 +958,8 @@ static void can_pernet_exit(struct net *net)
 
 static __init int can_init(void)
 {
+       int rc;
+
        /* check for correct padding to be able to use the structs similarly */
        BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
                     offsetof(struct canfd_frame, len) ||
@@ -971,15 +973,31 @@ static __init int can_init(void)
        if (!rcv_cache)
                return -ENOMEM;
 
-       register_pernet_subsys(&can_pernet_ops);
+       rc = register_pernet_subsys(&can_pernet_ops);
+       if (rc)
+               goto out_pernet;
 
        /* protocol register */
-       sock_register(&can_family_ops);
-       register_netdevice_notifier(&can_netdev_notifier);
+       rc = sock_register(&can_family_ops);
+       if (rc)
+               goto out_sock;
+       rc = register_netdevice_notifier(&can_netdev_notifier);
+       if (rc)
+               goto out_notifier;
+
        dev_add_pack(&can_packet);
        dev_add_pack(&canfd_packet);
 
        return 0;
+
+out_notifier:
+       sock_unregister(PF_CAN);
+out_sock:
+       unregister_pernet_subsys(&can_pernet_ops);
+out_pernet:
+       kmem_cache_destroy(rcv_cache);
+
+       return rc;
 }
 
 static __exit void can_exit(void)
-- 
1.8.3.1