[PATCH v2] power: supply: qcom_battmgr: fix use-after-free

qcom_battmgr_pdr_notify() queues enable_work when the PMIC GLINK service
comes up, and the worker recovers battmgr through container_of() to issue
firmware requests. The PMIC GLINK client stays on the client list until
its devres release action runs, so a PDR notification can keep queueing
the work, and a pending or running worker can access battmgr after devres
frees it.

Make enable_work device-managed with devm_work_autocancel(), registered
before the PMIC GLINK client is allocated. The devres cleanup then
releases the client first, so no further notification can queue the work,
and cancels the work before battmgr is freed.

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

Fixes: 29e8142b5623 ("power: supply: Introduce Qualcomm PMIC GLINK power supply")
Cc: [email protected]
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <[email protected]>
Link: https://patch.msgid.link/[email protected]
---
Changes in v2: use devm_work_autocancel() instead of a manual remove()
callback with disable_work_sync(), per Sebastian Reichel.

 drivers/power/supply/qcom_battmgr.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/qcom_battmgr.c b/drivers/power/supply/qcom_battmgr.c
index 490137a23d..362ad58068 100644
--- a/drivers/power/supply/qcom_battmgr.c
+++ b/drivers/power/supply/qcom_battmgr.c
@@ -5,6 +5,7 @@
  * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
  */
 #include <linux/auxiliary_bus.h>
+#include <linux/devm-helpers.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/nvmem-consumer.h>
@@ -1648,7 +1649,6 @@ static int qcom_battmgr_probe(struct auxiliary_device *adev,
 	psy_cfg_supply.supplied_to = qcom_battmgr_battery;
 	psy_cfg_supply.num_supplicants = 1;
 
-	INIT_WORK(&battmgr->enable_work, qcom_battmgr_enable_worker);
 	mutex_init(&battmgr->lock);
 	init_completion(&battmgr->ack);
 
@@ -1711,6 +1711,11 @@ static int qcom_battmgr_probe(struct auxiliary_device *adev,
 					     "failed to register wireless charing power supply\n");
 	}
 
+	ret = devm_work_autocancel(dev, &battmgr->enable_work,
+				   qcom_battmgr_enable_worker);
+	if (ret)
+		return ret;
+
 	battmgr->client = devm_pmic_glink_client_alloc(dev, PMIC_GLINK_OWNER_BATTMGR,
 						       qcom_battmgr_callback,
 						       qcom_battmgr_pdr_notify,
-- 
2.34.1