netdev - [PATCH v4 net 6/6] phonet: Handle error of rtnl_register

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241008184737.9619-7-kuniyu@amazon.com>
Date: Tue, 8 Oct 2024 11:47:37 -0700
From: Kuniyuki Iwashima <kuniyu@...zon.com>
To: "David S. Miller" <davem@...emloft.net>, Eric Dumazet
	<edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni
	<pabeni@...hat.com>
CC: Kuniyuki Iwashima <kuniyu@...zon.com>, Kuniyuki Iwashima
	<kuni1840@...il.com>, <netdev@...r.kernel.org>,
	Rémi Denis-Courmont <courmisch@...il.com>, "Florian
 Westphal" <fw@...len.de>
Subject: [PATCH v4 net 6/6] phonet: Handle error of rtnl_register_module().

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@...zon.com>
Acked-by: Rémi Denis-Courmont <courmisch@...il.com>
---
Cc: Florian Westphal <fw@...len.de>

v3: Add more context in changelog
v2: Make rtnl_msg_handler const
---
 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 7008d402499d..894e5c72d6bf 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);
 }
-- 
2.30.2