FAILED: patch "[PATCH] thermal: core: Free thermal zone ID later during removal" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x daae9c18feec74566e023fc88cfb0ce26e39d868
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051205-varnish-neurology-baf9@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From daae9c18feec74566e023fc88cfb0ce26e39d868 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Tue, 7 Apr 2026 15:58:34 +0200
Subject: [PATCH] thermal: core: Free thermal zone ID later during removal

The thermal zone removal ordering is different from the thermal zone
registration rollback path ordering and the former is arguably
problematic because freeing a thermal zone ID prematurely may cause
it to be used during the registration of another thermal zone which
may fail as a result.

Prevent that from occurring by changing the thermal zone removal
ordering to reflect the thermal zone registration rollback path
ordering.

Also more the ida_destroy() call from thermal_zone_device_unregister()
to thermal_release() for consistency.

Fixes: b31ef8285b19 ("thermal core: convert ID allocation to IDA")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/5063934.GXAFRqVoOG@rafael.j.wysocki

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 6e10b2fe2972..c1ec98591703 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -965,6 +965,7 @@ static void thermal_release(struct device *dev)
 		tz = to_thermal_zone(dev);
 		thermal_zone_destroy_device_groups(tz);
 		thermal_set_governor(tz, NULL);
+		ida_destroy(&tz->ida);
 		mutex_destroy(&tz->lock);
 		complete(&tz->removal);
 	} else if (!strncmp(dev_name(dev), "cooling_device",
@@ -1729,8 +1730,6 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 
 	thermal_thresholds_exit(tz);
 	thermal_remove_hwmon_sysfs(tz);
-	ida_free(&thermal_tz_ida, tz->id);
-	ida_destroy(&tz->ida);
 
 	device_del(&tz->device);
 	put_device(&tz->device);
@@ -1738,6 +1737,9 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 	thermal_notify_tz_delete(tz);
 
 	wait_for_completion(&tz->removal);
+
+	ida_free(&thermal_tz_ida, tz->id);
+
 	kfree(tz->tzp);
 	kfree(tz);
 }