| Message ID | 20230329122629.3614-1-rui.zhang@intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [v2,-next] thermal/drivers/thermal_hwmon: Fix a kernel NULL pointer dereference | expand |
On Wed, Mar 29, 2023 at 2:26 PM Zhang Rui <rui.zhang@intel.com> wrote: > > When the hwmon device node of a thermal zone device is not found, > using hwmon->device causes a kernel NULL pointer dereference. > > Skip removing hwmon device for thermal zones without hwmon device, and > fix the kernel NULL pointer dereference when hwmon device is not found. > > Fixes: dec07d399cc8 ("thermal: Don't use 'device' internal thermal zone structure field") > Reported-by: Preble Adam C <adam.c.preble@intel.com> Do you have a link to the bug report? I'm wondering where exactly it triggers. > Signed-off-by: Zhang Rui <rui.zhang@intel.com> > --- > v1 -> v2 > Add check for devices without hwmon device. > Use pr_debug instead of dev_dbg. > --- > drivers/thermal/thermal_hwmon.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c > index c59db17dddd6..1cdee2ee8d4d 100644 > --- a/drivers/thermal/thermal_hwmon.c > +++ b/drivers/thermal/thermal_hwmon.c > @@ -226,10 +226,12 @@ void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) > struct thermal_hwmon_device *hwmon; > struct thermal_hwmon_temp *temp; > > + if (tz->tzp && tz->tzp->no_hwmon) > + return; > + > hwmon = thermal_hwmon_lookup_by_type(tz); > if (unlikely(!hwmon)) { > - /* Should never happen... */ > - dev_dbg(hwmon->device, "hwmon device lookup failed!\n"); > + pr_debug("hwmon device lookup failed!\n"); > return; > } > > --
diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c index c59db17dddd6..1cdee2ee8d4d 100644 --- a/drivers/thermal/thermal_hwmon.c +++ b/drivers/thermal/thermal_hwmon.c @@ -226,10 +226,12 @@ void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) struct thermal_hwmon_device *hwmon; struct thermal_hwmon_temp *temp; + if (tz->tzp && tz->tzp->no_hwmon) + return; + hwmon = thermal_hwmon_lookup_by_type(tz); if (unlikely(!hwmon)) { - /* Should never happen... */ - dev_dbg(hwmon->device, "hwmon device lookup failed!\n"); + pr_debug("hwmon device lookup failed!\n"); return; }
When the hwmon device node of a thermal zone device is not found, using hwmon->device causes a kernel NULL pointer dereference. Skip removing hwmon device for thermal zones without hwmon device, and fix the kernel NULL pointer dereference when hwmon device is not found. Fixes: dec07d399cc8 ("thermal: Don't use 'device' internal thermal zone structure field") Reported-by: Preble Adam C <adam.c.preble@intel.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com> --- v1 -> v2 Add check for devices without hwmon device. Use pr_debug instead of dev_dbg. --- drivers/thermal/thermal_hwmon.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)