netdev - [PATCH net-next v7 02/25] rtnetlink: don't crash on unregister if no dellink exists

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: <20240917010734.1905-3-antonio@openvpn.net>
Date: Tue, 17 Sep 2024 03:07:11 +0200
From: Antonio Quartulli <antonio@...nvpn.net>
To: netdev@...r.kernel.org
Cc: kuba@...nel.org,
	pabeni@...hat.com,
	ryazanov.s.a@...il.com,
	edumazet@...gle.com,
	andrew@...n.ch,
	sd@...asysnail.net,
	Antonio Quartulli <antonio@...nvpn.net>
Subject: [PATCH net-next v7 02/25] rtnetlink: don't crash on unregister if no dellink exists

rtnl_unregister_ops calls __rtnl_links_kill which calls
unconditionally ops->dellink on any related interface.

However, if a module hasn't implemented dellink, this
invocation will crash.

Add a check to avoid calling dellink when NULL and rather
invoke netdevice_unregister_queue to schedule unregistering
the device as usual.

Signed-off-by: Antonio Quartulli <antonio@...nvpn.net>
---
 net/core/rtnetlink.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index f0a520987085..7e7fcd319af8 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -453,8 +453,12 @@ static void __rtnl_kill_links(struct net *net, struct rtnl_link_ops *ops)
 	LIST_HEAD(list_kill);
 
 	for_each_netdev(net, dev) {
-		if (dev->rtnl_link_ops == ops)
-			ops->dellink(dev, &list_kill);
+		if (dev->rtnl_link_ops == ops) {
+			if (ops->dellink)
+				ops->dellink(dev, &list_kill);
+			else
+				unregister_netdevice_queue(dev, &list_kill);
+		}
 	}
 	unregister_netdevice_many(&list_kill);
 }
-- 
2.44.2