From 04efcee6ef8d0f01eef495db047e7216d6e6e38f Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Fri, 4 Apr 2025 09:11:22 -0700 Subject: net: hold instance lock during NETDEV_CHANGE Cosmin reports an issue with ipv6_add_dev being called from NETDEV_CHANGE notifier: [ 3455.008776] ? ipv6_add_dev+0x370/0x620 [ 3455.010097] ipv6_find_idev+0x96/0xe0 [ 3455.010725] addrconf_add_dev+0x1e/0xa0 [ 3455.011382] addrconf_init_auto_addrs+0xb0/0x720 [ 3455.013537] addrconf_notify+0x35f/0x8d0 [ 3455.014214] notifier_call_chain+0x38/0xf0 [ 3455.014903] netdev_state_change+0x65/0x90 [ 3455.015586] linkwatch_do_dev+0x5a/0x70 [ 3455.016238] rtnl_getlink+0x241/0x3e0 [ 3455.019046] rtnetlink_rcv_msg+0x177/0x5e0 Similarly, linkwatch might get to ipv6_add_dev without ops lock: [ 3456.656261] ? ipv6_add_dev+0x370/0x620 [ 3456.660039] ipv6_find_idev+0x96/0xe0 [ 3456.660445] addrconf_add_dev+0x1e/0xa0 [ 3456.660861] addrconf_init_auto_addrs+0xb0/0x720 [ 3456.661803] addrconf_notify+0x35f/0x8d0 [ 3456.662236] notifier_call_chain+0x38/0xf0 [ 3456.662676] netdev_state_change+0x65/0x90 [ 3456.663112] linkwatch_do_dev+0x5a/0x70 [ 3456.663529] __linkwatch_run_queue+0xeb/0x200 [ 3456.663990] linkwatch_event+0x21/0x30 [ 3456.664399] process_one_work+0x211/0x610 [ 3456.664828] worker_thread+0x1cc/0x380 [ 3456.665691] kthread+0xf4/0x210 Reclassify NETDEV_CHANGE as a notifier that consistently runs under the instance lock. Link: https://lore.kernel.org/netdev/aac073de8beec3e531c86c101b274d434741c28e.camel@nvidia.com/ Reported-by: Cosmin Ratiu Tested-by: Cosmin Ratiu Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250404161122.3907628-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index cf3b6445817b..2d11d013cabe 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4429,6 +4429,7 @@ void linkwatch_fire_event(struct net_device *dev); * pending work list (if queued). */ void linkwatch_sync_dev(struct net_device *dev); +void __linkwatch_sync_dev(struct net_device *dev); /** * netif_carrier_ok - test if carrier present @@ -4974,6 +4975,7 @@ void dev_set_rx_mode(struct net_device *dev); int dev_set_promiscuity(struct net_device *dev, int inc); int netif_set_allmulti(struct net_device *dev, int inc, bool notify); int dev_set_allmulti(struct net_device *dev, int inc); +void netif_state_change(struct net_device *dev); void netdev_state_change(struct net_device *dev); void __netdev_notify_peers(struct net_device *dev); void netdev_notify_peers(struct net_device *dev); -- cgit v1.2.3