Re: [PATCH 4.4-stable] slip: stop double free sl->dev in slip_open

[yangerkun <yangerkun@huawei.com>]

cc David and netdev mail list too.

On 2020/2/22 17:46, yangerkun wrote:
> After commit e4c157955483 ("slip: Fix use-after-free Read in slip_open"),
> we will double free sl->dev since sl_free_netdev will free sl->dev too.
> It's fine for mainline since sl_free_netdev in mainline won't free
> sl->dev.
> 
> Signed-off-by: yangerkun <yangerkun@huawei.com>
> ---
>   drivers/net/slip/slip.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/net/slip/slip.c b/drivers/net/slip/slip.c
> index ef6b25ec75a1..7fe9183fad0e 100644
> --- a/drivers/net/slip/slip.c
> +++ b/drivers/net/slip/slip.c
> @@ -861,7 +861,6 @@ err_free_chan:
>   	tty->disc_data = NULL;
>   	clear_bit(SLF_INUSE, &sl->flags);
>   	sl_free_netdev(sl->dev);
> -	free_netdev(sl->dev);
>   
>   err_exit:
>   	rtnl_unlock();
>