Re: potential null dereference in sysfs_override_clocksource()

From: Thomas Gleixner
Date: Sun Jul 19 2009 - 11:13:17 EST


Dan,

On Sun, 19 Jul 2009, Dan Carpenter wrote:

> Hello,
>
> I am testing a source checker (http://repo.or.cz/w/smatch.git).
>
> It found an issue in sysfs_override_clocksource() from
> kernel/time/clocksource.c. If "len" is zero then "ovr" is null and
> checking ovr->flags will oops on line 517.
>
> kernel/time/clocksource.c
> 516 if (tick_oneshot_mode_active() &&
> 517 !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {
> 518 printk(KERN_WARNING "%s clocksource is not HRT compatible. "

Indeed. I queued a fix.

Thanks for pointing it out,


tglx
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