[Devel] [PATCH rh7 1/2] ms/ixgbe: fix possible deadlock in ixgbe_service_task()

[Kirill Tkhai]

On 10.01.2020 18:31, Konstantin Khorenko wrote:
> From: Taehee Yoo <ap420073 at gmail.com>
> 
> ixgbe_service_task() calls unregister_netdev() under rtnl_lock().
> But unregister_netdev() internally calls rtnl_lock().
> So deadlock would occur.
> 
> Fixes: 59dd45d550c5 ("ixgbe: firmware recovery mode")
> Signed-off-by: Taehee Yoo <ap420073 at gmail.com>
> Tested-by: Andrew Bowers <andrewx.bowers at intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher at intel.com>
> Signed-off-by: David S. Miller <davem at davemloft.net>
> 
> https://jira.sw.ru/browse/PSBM-100722
> 
> (cherry picked from commit 8b6381600d59871fbe44d36522272f961ab42410)
> Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>

Acked-by: Kirill Tkhai <ktkhai at virtuozzo.com>

> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index eb87979187cb8..eef479f762f93 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -7950,11 +7950,8 @@ static void ixgbe_service_task(struct work_struct *work)
>  		return;
>  	}
>  	if (ixgbe_check_fw_error(adapter)) {
> -		if (!test_bit(__IXGBE_DOWN, &adapter->state)) {
> -			rtnl_lock();
> +		if (!test_bit(__IXGBE_DOWN, &adapter->state))
>  			unregister_netdev(adapter->netdev);
> -			rtnl_unlock();
> -		}
>  		ixgbe_service_event_complete(adapter);
>  		return;
>  	}
>