Re: [PATCH] net: net_failover: Fix the deadlock in net_failover_slave_name_change()

[Hangbin Liu]

On Tue, Sep 08, 2026 at 12:06:29PM +0800, faicker.mo@xxxxxxxxx wrote:
> From: Faicker Mo <faicker.mo@xxxxxxxxx>
> 
> This is a sibling fix of commit
> b84c5632c7b3 ("net: net_failover: Fix the deadlock in slave register").
> There is netdev_lock_ops() in the upper callers, so using netif_open()
> instead of dev_open().
> 
> Call Trace:
>  __schedule+0x2bb/0x650
>  schedule+0x27/0xb0
>  schedule_preempt_disabled+0x15/0x30
>  __mutex_lock.constprop.0+0x550/0xaf0
>  __mutex_lock_slowpath+0x13/0x20
>  mutex_lock+0x3b/0x50
>  dev_open+0x3b/0xe0
>  net_failover_slave_name_change+0x22/0x40
>  failover_event+0xd4/0x1e0
>  notifier_call_chain+0x62/0xf0
>  raw_notifier_call_chain+0x16/0x30
>  call_netdevice_notifiers_info+0x50/0x80
>  netif_change_name+0x200/0x330
>  do_setlink.isra.0+0xb12/0xdf0
>  ? security_capable+0x9a/0x1e0
>  ? ns_capable+0x31/0x60
>  rtnl_setlink+0x302/0x670
>  ? netlink_recvmsg+0x296/0x340
>  ? security_capable+0x9a/0x1e0
>  ? __pfx_rtnl_setlink+0x10/0x10
>  rtnetlink_rcv_msg+0x384/0x460
>  ? __pfx_rtnetlink_rcv_msg+0x10/0x10
>  netlink_rcv_skb+0x61/0x120
>  rtnetlink_rcv+0x15/0x30
>  netlink_unicast+0x28f/0x3c0
>  netlink_sendmsg+0x216/0x450
>  __sys_sendto+0x222/0x230
>  __x64_sys_sendto+0x24/0x40
>  x64_sys_call+0x1d5d/0x2390
>  do_syscall_64+0x105/0x5a0
>  ? do_syscall_64+0x140/0x5a0
>  ? exc_page_fault+0x94/0x1e0
>  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> 
> Fixes: 7e4d784f5810 ("net: hold netdev instance lock during rtnetlink operations")
> Signed-off-by: Faicker Mo <faicker.mo@xxxxxxxxx>
> ---
>  drivers/net/net_failover.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c
> index 3f7d31033bae..1b5213e87070 100644
> --- a/drivers/net/net_failover.c
> +++ b/drivers/net/net_failover.c
> @@ -675,7 +675,7 @@ static int net_failover_slave_name_change(struct net_device *slave_dev,
>  	/* We need to bring up the slave after the rename by udev in case
>  	 * open failed with EBUSY when it was registered.
>  	 */
> -	dev_open(slave_dev, NULL);
> +	netif_open(slave_dev, NULL);
>  
>  	return 0;
>  }
> -- 
> 2.53.0
> 

Reviewed-by: Hangbin Liu <liuhangbin@xxxxxxxxxx>