Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Wed, 29 Mar 2023 14:06:34 +0200 | Subject | Re: [PATCH -next] thermal/drivers/thermal_hwmon: Fix a kernel NULL pointer dereference |
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On Wed, Mar 29, 2023 at 11:57 AM Daniel Lezcano <daniel.lezcano@linaro.org> wrote: > > On 29/03/2023 11:00, Zhang Rui wrote: > > When the hwmon device node of a thermal zone device is not found, > > using hwmon->device causes a kernel NULL pointer dereference. > > > > Reported-by: Preble Adam C <adam.c.preble@intel.com> > > Signed-off-by: Zhang Rui <rui.zhang@intel.com> > > --- > > Fixes: dec07d399cc8 ("thermal: Don't use 'device' internal thermal zone structure field") > > dec07d399cc8 is a commit in the linux-next branch of linux-pm repo. > > I'm not sure if the Fix tag applies to such commit or not. > > Actually it reverts the work done to encapsulate the thermal zone device > structure.
So maybe instead of the wholesale switch to using "driver-specific" device pointers for printing messages, something like thermal_zone_debug/info/warn/error() taking a thermal zone pointer as the first argument can be defined?
At least this particular bug could be avoided this way.
> > --- > > drivers/thermal/thermal_hwmon.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c > > index c59db17dddd6..261743f461be 100644 > > --- a/drivers/thermal/thermal_hwmon.c > > +++ b/drivers/thermal/thermal_hwmon.c > > @@ -229,7 +229,7 @@ void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) > > hwmon = thermal_hwmon_lookup_by_type(tz); > > if (unlikely(!hwmon)) { > > /* Should never happen... */ > > - dev_dbg(hwmon->device, "hwmon device lookup failed!\n"); > > + dev_dbg(&tz->device, "hwmon device lookup failed!\n"); > > As it 'Should never happen', I would replace that by: > > if (WARN_ON(!hwmon)) > /* Should never happen... */ > return; > > > > > return; > > } > > > > -- > <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs > > Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | > <http://twitter.com/#!/linaroorg> Twitter | > <http://www.linaro.org/linaro-blog/> Blog >
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