Re: [PATCH v2] net: alx: fix race condition in alx_remove

[David Miller]

From: Zekun Shen <bruceshenzk@xxxxxxxxx>
Date: Mon, 15 Jun 2020 11:50:29 -0400

> There is a race condition exist during termination. The path is
> alx_stop and then alx_remove. An alx_schedule_link_check could be called
> before alx_stop by interrupt handler and invoke alx_link_check later.
> Alx_stop frees the napis, and alx_remove cancels any pending works.
> If any of the work is scheduled before termination and invoked before
> alx_remove, a null-ptr-deref occurs because both expect alx->napis[i].
> 
> This patch fix the race condition by moving cancel_work_sync functions
> before alx_free_napis inside alx_stop. Because interrupt handler can call
> alx_schedule_link_check again, alx_free_irq is moved before
> cancel_work_sync calls too.
> 
> Signed-off-by: Zekun Shen <bruceshenzk@xxxxxxxxx>

Applied, thank you.