Re: [syzbot] WARNING in rtl8152_probe

On Fri, May 14, 2021 at 07:50:19AM +0000, Hayes Wang wrote:

Greg KH [off-list ref]

quoted

Sent: Friday, May 14, 2021 2:49 PM

[...]

quoted

Because people can create "bad" devices and plug them into a system
which causes the driver to load and then potentially crash the system or
do other bad things.

USB drivers now need to be able to handle "malicious" devices, it's been
that way for many years now.

My question is that even I check whole the USB descriptor, the malicious
devices could duplicate it easily to pass my checks. That is, I could add a
lot of checks, but it still doesn't prevent malicious devices. Is this meaningful?

Checking the whole USB decriptor is fine, yes, they can duplicate that.
So that means you need to validate _ALL_ data coming from the device
that it is in an acceptable range of values that the driver can
correctly handle.

thanks,

greg k-h