Re: Re: [PATCH] staging: rtl8712: check register_netdev() return value
From: Dan Carpenter
Date: Thu Dec 10 2020 - 10:18:11 EST
On Thu, Dec 10, 2020 at 11:05:34PM +0800, shaojie.dong@xxxxxxxxxxxxxxxx wrote:
> Hi
>
> >
> > This function should not be calling register_netdev(). What does that
> > have to do with firmware? It should also not free_netdev() because
> > that will just lead to a use after free in the caller.
> >
>
> --> check code history author<larry.finger@xxxxxxxxxxxx> changed synchronous firmware loading to asynchronous firmware loading
> before this change, register_netdev() was not calling in firmware related function.
> For asynchronous loading, maybe register_netdev() be calling in rtl871x_load_fw_cb() is to ensure the netdev be registered after firmware loading completed
>
> --> for potential use after free issue
> Could I only call "free_irq(adapter->pnetdev->irq, adapter->pnetdev)" when register_netdev() failed ?
> If no need to change drivers/staging/rtl8712/hal_init.c file, I could give up my patch, thank you !
>
Cleaning this up is a bit complicated and requires reworking the
firmware loading and it requires testing. I don't think you have the
hardware to actually test this driver? Probably, just leave this code
for another day.
regards,
dan carpenter