6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kuniyuki Iwashima kuniyu@amazon.com
[ 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@amazon.com Acked-by: Rémi Denis-Courmont courmisch@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/phonet/pn_netlink.c | 28 +++++++++++----------------- 1 file changed, 11 insertions(+), 17 deletions(-)
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); }