RE: [syzbot] WARNING in rtl8152_probe

Alan Stern [off-list ref]

Sent: Friday, May 14, 2021 11:33 PM

[...]

The real motivation here, which nobody has mentioned explicitly yet, is
that the driver needs to be careful enough that it won't crash no matter
what bizarre, malfunctioning, or malicious device is attached.

Even if a device isn't malicious, if it is buggy, broken, or
malfunctioning in some way then it can present input that a normal
device would never generate.  If the driver isn't prepared to handle
this unusual input, it may crash.  That is specifically what we want to
avoid.

So if a peculiar emulated device created by syzbot is capable of
crashing the driver, then somewhere there is a bug which needs to be
fixed.  It's true that fixing all these bugs might not protect against a
malicious device which deliberately behaves in an apparently reasonable
manner.  But it does reduce the attack surface.

Thanks for your response.
I will add some checks.

Best Regards,
Hayes