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

From: Andreas Mohr <andi@lisas.de>
To: Zhang Rui <rui.zhang@intel.com>
Cc: linux-kernel@vger.kernel.org
Subject: [ASAP] thermal_sys.c NULL ptr deref patch likely incomplete
Date: Thu, 14 Feb 2013 15:44:04 +0100	[thread overview]
Message-ID: <20130214144404.GA20011@rhlx01.hs-esslingen.de> (raw)

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?)

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