Re: [PATCH] net: usb: asix: fill null-ptr-deref in asix_suspend

[Andrey Konovalov]

On Mon, Nov 6, 2017 at 4:20 PM, Oliver Neukum <oneukum@xxxxxxxx> wrote:
> Am Montag, den 06.11.2017, 13:30 +0100 schrieb Andrey Konovalov:
>> On Mon, Nov 6, 2017 at 10:49 AM, Oliver Neukum <oneukum@xxxxxxxx> wrote:
>> >
>> >
>> > 2. Will a device work after that? The appropriate fix may be to wait
>> > until the device is properly initialized.
>>
>> This shouldn't affect real devices as far as I understand. The crash
>> can be caused by a crafted malicious device.
>
> Hi!
>
> Hm. That seems strange as driver_priv is kmalloced. Do you
> still have a descriptor that causes this?
> Shouldn't we rather reject such a broken device?

I do have a way to reproduce this.

As far as I understand, for this particular device ax88172_bind() is
called, which doesn't assign anything to dev->driver_priv, so that's
why it is NULL in suspend() and resume().

>
>         Regards
>                 Oliver
>