RE: [ASAP] thermal_sys.c NULL ptr deref patch likely incomplete

From: Zhang, Rui
Date: Fri Feb 15 2013 - 04:56:27 EST




> -----Original Message-----
> From: Andreas Mohr [mailto:andi@xxxxxxxx]
> Sent: Thursday, February 14, 2013 10:44 PM
> To: Zhang, Rui
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Subject: [ASAP] thermal_sys.c NULL ptr deref patch likely incomplete
> Importance: High
>
> Hi,
>
> I just had a
>
> # cat /sys/class/thermal/thermal_zone0/policy
> (null)
>
>
> When looking at the code (on my -rc7), I saw:
>
> drivers/thermal/thermal_sys.c
>
> static ssize_t
> policy_show(struct device *dev, struct device_attribute *devattr, char
> *buf)
> {
> struct thermal_zone_device *tz = to_thermal_zone(dev);
>
> return sprintf(buf, "%s\n", tz->governor->name);
> }
>
>
> (not sure though why I manage to get a "(null)" rather than a crash
> due to the dereferencing prior to output - possibly since I do have a
> valid governor allocated yet then only its name field is null?)
>
Hmm,

Please apply the debug patch and see what you can get here.

Thanks,
rui
>
> Seems we are missing a critical (and -rc-relevant) patch here
> (and perhaps at other locations in this file, too, given that
> this one was missed last time?).
>
> Currently trying to get acerhdf operation into a working state
> (and having some trouble with it - didn't know that I probably need
> some
> governor setup which seems to have just been available on my last setup,
> or so)
>
> Thanks,
>
> Andreas Mohr

Attachment: acerhdf-debug-2.patch
Description: acerhdf-debug-2.patch