Re: signed integer overflow in common_timer_get on linux 4.15.0-rc1

[Dan Carpenter <dan.carpenter () oracle com>]

On Thu, Dec 07, 2017 at 12:17:18PM +0100, Greg KH wrote:
> On Thu, Dec 07, 2017 at 06:01:43PM +0800, at zhou wrote:
> > Hi all,
> >
> > credit   to   L5@360vulcan team
> >
> > I fuzzed the linux kernel and find signed integer overflow on linux
> > 4.15.0-rc1+.
> > the crash log can see below, the .config and the poc file ,please see the
> > attachments.
>
> Odd, doesn't seem to affect a 4.9 or 4.15-rc2 kernel here on my
> machines, is there something specific in the .config that might be
> triggering this?

Greg, you're running with UBSAN?

I've always wondered how UBSAN was going to work because there are *so*
many harmless integer overflows in the kernel.  That's my main challenge
with trying to use static analysis for integer overflows.

regards,
dan carpenter