Subject: Re: [syzbot] WARNING in rtl8152_probe

From: Dan Carpenter <[email-masked]>
Date: Fri, 14 May 2021 09:41:38 +0300

On Fri, May 14, 2021 at 02:58:00AM +0000, Hayes Wang wrote:
> Alan Stern <[email-masked]>
> > Sent: Thursday, May 13, 2021 10:26 PM
> [...]
> > Syzbot doesn't test real devices.  It tests emulations, and the emulated
> > devices usually behave very strangely and in very peculiar and
> > unexpected ways, so as to trigger bugs in the kernel.  That's why the
> > USB devices you see in syzbot logs usually have bizarre descriptors.
> 
> Do you mean I have to debug for a device which doesn't exist?
> I don't understand why I must consider a fake device
> which provide unexpected USB descriptor deliberately?

Imagine you are at a conference and two people sit down next to you, one
on either side.  The one accidentally spills coffee on your lap.  The
other plugs in a USB device to your laptop.  Now you are infected with
spyware.

https://elie.net/blog/security/what-are-malicious-usb-keys-and-how-to-create-a-realistic-one/

regards,
dan carpenter