Commit b5e837c8 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Paolo Abeni
Browse files

phonet: Handle error of rtnl_register_module(). 



Before commit addf9b90 ("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: addf9b90 ("net: rtnetlink: use rcu to free rtnl message handlers")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: default avatarRémi Denis-Courmont <courmisch@gmail.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 5be2062e

net/phonet/pn_netlink.c

+11 −17
Original line number Diff line number Diff line
@@ -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);

}