From d4c6bfc83936cb61fac99e9891c406fbdd40f964 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 17 Feb 2025 11:11:29 -0800 Subject: [PATCH] dev: Use rtnl_net_dev_lock() in unregister_netdev(). The following sequence is basically illegal when dev was fetched without lookup because dev_net(dev) might be different after holding rtnl_net_lock(): net = dev_net(dev); rtnl_net_lock(net); Let's use rtnl_net_dev_lock() in unregister_netdev(). Note that there is no real bug in unregister_netdev() for now because RTNL protects the scope even if dev_net(dev) is changed before/after RTNL. Fixes: 00fb9823939e ("dev: Hold per-netns RTNL in (un)?register_netdev().") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250217191129.19967-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- net/core/dev.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 19e268568282..fafd2f4b5d5d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11920,11 +11920,9 @@ EXPORT_SYMBOL(unregister_netdevice_many); */ void unregister_netdev(struct net_device *dev) { - struct net *net = dev_net(dev); - - rtnl_net_lock(net); + rtnl_net_dev_lock(dev); unregister_netdevice(dev); - rtnl_net_unlock(net); + rtnl_net_dev_unlock(dev); } EXPORT_SYMBOL(unregister_netdev);