thermal: core: Fix NULL pointer dereference in zone registration error path
PATCH 1/1 thermal: core: Fix NULL pointer dereference in zone registration error path
From: Rafael J. Wysocki <[email protected]>
If device_register() in thermal_zone_device_register_with_trips() returns an error, the tz variable is set to NULL and subsequently dereferenced in kfree(tz->tzp).
Commit adc8749b150c ("thermal/drivers/core: Use put_device() if device_register() fails") added the tz = NULL assignment in question to avoid a possible double-free after dropping the reference to the zone device. However, after commit 4649620d9404 ("thermal: core: Make thermal_zone_device_unregister() return after freeing the zone"), that assignment has become redundant, because dropping the reference to the zone device does not cause the zone object to be freed any more.
Drop it to address the NULL pointer dereference.
--- drivers/thermal/thermal_core.c | 1 - 1 file changed, 1 deletion(-)
drivers/thermal/thermal_core.c +0 -1
@@ -1394,7 +1394,6 @@ unregister:device_del (&tz->device); release_device:put_device (&tz->device); - tz =NULL ; remove_id:ida_free (&thermal_tz_ida, id); free_tzp:
Quoted 30 lines · Rafael J. Wysocki
From: Rafael J. Wysocki <[email protected]>
If
device_register()inthermal_zone_device_register_with_trips()returns an error, the tz variable is set to NULL and subsequently dereferenced inkfree(tz->tzp).Commit
adc8749b150c("thermal/drivers/core: Useput_device()ifdevice_register()fails") added the tz = NULL assignment in question to avoid a possible double-free after dropping the reference to the zone device. However, after commit4649620d9404("thermal: core: Makethermal_zone_device_unregister()return after freeing the zone"), that assignment has become redundant, because dropping the reference to the zone device does not cause the zone object to be freed any more.Drop it to address the NULL pointer dereference.
Fixes 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone parameters structure")Signed-off-by Rafael J. Wysocki <[email protected]>--- drivers/thermal/thermal_core.c | 1 - 1 file changed, 1 deletion(-)Index:
linux-pm/drivers/thermal/thermal_core.c
===================================================================
drivers/thermal/thermal_core.c unregister: · line 1399
Quoted 7 lines
drivers/thermal/thermal_core.c +0
-1@@ -1394,7 +1394,6 @@ unregister:device_del (&tz->device); release_device:put_device (&tz->device); - tz =NULL ; remove_id:ida_free (&thermal_tz_ida, id); free_tzp: