This is a note to let you know that I've just added the patch titled
thermal: core: Fix NULL pointer dereference in zone registration error path
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
thermal-core-fix-null-pointer-dereference-in-zone-re.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b42c78f8df71124d210c02ab4bf5befe3a70f950
Author: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Date: Thu Dec 14 11:52:25 2023 +0100
thermal: core: Fix NULL pointer dereference in zone registration error path
[ Upstream commit 04e6ccfc93c5a1aa1d75a537cf27e418895e20ea ]
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.
Fixes: 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone parameters structure")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Reviewed-by: Lukasz Luba <lukasz.luba@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index e6f3166a9208..2de524fb7be5 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1382,7 +1382,6 @@ thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *t
device_del(&tz->device);
release_device:
put_device(&tz->device);
- tz = NULL;
remove_id:
ida_free(&thermal_tz_ida, id);
free_tzp:
