Patch "phonet: 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

    phonet: 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:
     phonet-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 4b1bf8eeeb2d62394fb92d5ba71ddecd79bbc787
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date:   Tue Oct 8 11:47:37 2024 -0700

    phonet: Handle error of rtnl_register_module().
    
    [ Upstream commit b5e837c86041bef60f36cf9f20a641a30764379a ]
    
    Before commit addf9b90de22 ("net: rtnetlink: use rcu to free rtnl
    message handlers"), once the first rtnl_register_module() allocated
    rtnl_msg_handlers[PF_PHONET], the following calls never failed.
    
    However, after the commit, rtnl_register_module() could fail silently
    to allocate rtnl_msg_handlers[PF_PHONET][msgtype] and requires error
    handling for each call.
    
    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 use rtnl_register_many() to handle the errors easily.
    
    Fixes: addf9b90de22 ("net: rtnetlink: use rcu to free rtnl message handlers")
    Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
    Acked-by: Rémi Denis-Courmont <courmisch@xxxxxxxxx>
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c
index 7008d402499d5..894e5c72d6bff 100644
--- a/net/phonet/pn_netlink.c
+++ b/net/phonet/pn_netlink.c
@@ -285,23 +285,17 @@ static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 	return err;
 }
 
+static const struct rtnl_msg_handler phonet_rtnl_msg_handlers[] __initdata_or_module = {
+	{THIS_MODULE, PF_PHONET, RTM_NEWADDR, addr_doit, NULL, 0},
+	{THIS_MODULE, PF_PHONET, RTM_DELADDR, addr_doit, NULL, 0},
+	{THIS_MODULE, PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, 0},
+	{THIS_MODULE, PF_PHONET, RTM_NEWROUTE, route_doit, NULL, 0},
+	{THIS_MODULE, PF_PHONET, RTM_DELROUTE, route_doit, NULL, 0},
+	{THIS_MODULE, PF_PHONET, RTM_GETROUTE, NULL, route_dumpit,
+	 RTNL_FLAG_DUMP_UNLOCKED},
+};
+
 int __init phonet_netlink_register(void)
 {
-	int err = rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_NEWADDR,
-				       addr_doit, NULL, 0);
-	if (err)
-		return err;
-
-	/* Further rtnl_register_module() cannot fail */
-	rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_DELADDR,
-			     addr_doit, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_GETADDR,
-			     NULL, getaddr_dumpit, 0);
-	rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_NEWROUTE,
-			     route_doit, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_DELROUTE,
-			     route_doit, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_GETROUTE,
-			     NULL, route_dumpit, RTNL_FLAG_DUMP_UNLOCKED);
-	return 0;
+	return rtnl_register_many(phonet_rtnl_msg_handlers);
 }