Patch "mpls: Handle error of rtnl_register_module()." has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    mpls: Handle error of rtnl_register_module().

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mpls-handle-error-of-rtnl_register_module.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2bf9273c96e40673368dba3ab8f6a53e5aafbb9c
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date:   Tue Oct 8 11:47:36 2024 -0700

    mpls: Handle error of rtnl_register_module().
    
    [ Upstream commit 5be2062e3080e3ff6707816caa445ec0c6eaacf7 ]
    
    Since introduced, mpls_init() has been ignoring the returned
    value of rtnl_register_module(), which could fail silently.
    
    Handling the error allows users to view a module as an all-or-nothing
    thing in terms of the rtnetlink functionality.  This prevents syzkaller
    from reporting spurious errors from its tests, where OOM often occurs
    and module is automatically loaded.
    
    Let's handle the errors by rtnl_register_many().
    
    Fixes: 03c0566542f4 ("mpls: Netlink commands to add, remove, and dump routes")
    Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index ba034fcd59f0d..43e8343df0db7 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -2729,6 +2729,15 @@ static struct rtnl_af_ops mpls_af_ops __read_mostly = {
 	.get_stats_af_size = mpls_get_stats_af_size,
 };
 
+static const struct rtnl_msg_handler mpls_rtnl_msg_handlers[] __initdata_or_module = {
+	{THIS_MODULE, PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, 0},
+	{THIS_MODULE, PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, 0},
+	{THIS_MODULE, PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes, 0},
+	{THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
+	 mpls_netconf_get_devconf, mpls_netconf_dump_devconf,
+	 RTNL_FLAG_DUMP_UNLOCKED},
+};
+
 static int __init mpls_init(void)
 {
 	int err;
@@ -2747,24 +2756,25 @@ static int __init mpls_init(void)
 
 	rtnl_af_register(&mpls_af_ops);
 
-	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
-			     mpls_rtm_newroute, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
-			     mpls_rtm_delroute, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
-			     mpls_getroute, mpls_dump_routes, 0);
-	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
-			     mpls_netconf_get_devconf,
-			     mpls_netconf_dump_devconf,
-			     RTNL_FLAG_DUMP_UNLOCKED);
-	err = ipgre_tunnel_encap_add_mpls_ops();
+	err = rtnl_register_many(mpls_rtnl_msg_handlers);
 	if (err)
+		goto out_unregister_rtnl_af;
+
+	err = ipgre_tunnel_encap_add_mpls_ops();
+	if (err) {
 		pr_err("Can't add mpls over gre tunnel ops\n");
+		goto out_unregister_rtnl;
+	}
 
 	err = 0;
 out:
 	return err;
 
+out_unregister_rtnl:
+	rtnl_unregister_many(mpls_rtnl_msg_handlers);
+out_unregister_rtnl_af:
+	rtnl_af_unregister(&mpls_af_ops);
+	dev_remove_pack(&mpls_packet_type);
 out_unregister_pernet:
 	unregister_pernet_subsys(&mpls_net_ops);
 	goto out;