[PATCH 6.1.y 2/2] power: supply: rt9455: quiesce delayed work before teardown

[Sasha Levin <sashal@kernel.org>]

From: Fan Wu <fanwu01@zju.edu.cn>

[ Upstream commit 3e7a1ebc32fad5a558254a478efd401c17a24381 ]

The threaded IRQ handler can queue pwr_rdy_work,
max_charging_time_work and batt_presence_work.  pwr_rdy_work and
batt_presence_work can also queue max_charging_time_work, while
batt_presence_work can requeue itself.

rt9455_remove() cancels max_charging_time_work before
batt_presence_work.  The latter can therefore queue
max_charging_time_work after it has already been cancelled:

  rt9455_remove()                   workqueue
    cancel pwr_rdy_work
    cancel max_charging_time_work
                                      batt_presence_work queues
                                        max_charging_time_work
    cancel batt_presence_work
    return
    devres frees rt9455_info
                                      max_charging_time_work dereferences
                                        rt9455_info

The IRQ also remains registered until devres cleanup and can queue more
work after any of the cancellation calls.  If rt9455_hw_init() fails
after the IRQ has been requested, probe returns without cancelling work
that may already have been queued.  A pending callback can then access
rt9455_info after it has been freed.

Register rt9455_cancel_all_delayed_works() through
devm_add_action_or_reset() right after devm_power_supply_register().
devres invokes the action in reverse registration order, after the
managed IRQ has been freed and before rt9455_info is released, so the
delayed works are drained in both rt9455_remove() and the probe error
path.  Cancel pwr_rdy_work and batt_presence_work before
max_charging_time_work because both can queue the latter.

This issue was found by an in-house static analysis tool.

Fixes: e86d69dd786e ("power_supply: Add support for Richtek RT9455 battery charger")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260723225310.12663-1-fanwu01@zju.edu.cn
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/rt9455_charger.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/rt9455_charger.c b/drivers/power/supply/rt9455_charger.c
index dd4ff038814f4..62ffc3acc2aec 100644
--- a/drivers/power/supply/rt9455_charger.c
+++ b/drivers/power/supply/rt9455_charger.c
@@ -1583,6 +1583,19 @@ static const struct regmap_config rt9455_regmap_config = {
 	.cache_type	= REGCACHE_RBTREE,
 };
 
+static void rt9455_cancel_all_delayed_works(void *data)
+{
+	struct rt9455_info *info = data;
+
+	/*
+	 * Both pwr_rdy_work and batt_presence_work can queue
+	 * max_charging_time_work, so cancel them first.
+	 */
+	cancel_delayed_work_sync(&info->pwr_rdy_work);
+	cancel_delayed_work_sync(&info->batt_presence_work);
+	cancel_delayed_work_sync(&info->max_charging_time_work);
+}
+
 static int rt9455_probe(struct i2c_client *client)
 {
 	struct i2c_adapter *adapter = client->adapter;
@@ -1673,6 +1686,10 @@ static int rt9455_probe(struct i2c_client *client)
 		goto put_usb_notifier;
 	}
 
+	ret = devm_add_action_or_reset(dev, rt9455_cancel_all_delayed_works, info);
+	if (ret)
+		goto put_usb_notifier;
+
 	ret = devm_request_threaded_irq(dev, client->irq, NULL,
 					rt9455_irq_handler_thread,
 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
@@ -1713,10 +1730,6 @@ static void rt9455_remove(struct i2c_client *client)
 	if (info->nb.notifier_call)
 		usb_unregister_notifier(info->usb_phy, &info->nb);
 #endif
-
-	cancel_delayed_work_sync(&info->pwr_rdy_work);
-	cancel_delayed_work_sync(&info->max_charging_time_work);
-	cancel_delayed_work_sync(&info->batt_presence_work);
 }
 
 static const struct i2c_device_id rt9455_i2c_id_table[] = {
-- 
2.53.0