[PATCH 6.6.y] power: supply: qcom_battmgr: fix use-after-free

[Sasha Levin <sashal@kernel.org>]

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

[ Upstream commit 4e40befedfc8ed86f44e1f81df92d13c149c9f8d ]

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: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260731022006.317192-1-fanwu01@zju.edu.cn
Link: https://patch.msgid.link/20260801051923.354496-1-fanwu01@zju.edu.cn
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
[ added the missing int ret declaration in qcom_battmgr_probe() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/qcom_battmgr.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/qcom_battmgr.c b/drivers/power/supply/qcom_battmgr.c
index e5eade1328163..326cddfb8e347 100644
--- a/drivers/power/supply/qcom_battmgr.c
+++ b/drivers/power/supply/qcom_battmgr.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2022, Linaro Ltd
  */
 #include <linux/auxiliary_bus.h>
+#include <linux/devm-helpers.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of_device.h>
@@ -1329,6 +1330,7 @@ static int qcom_battmgr_probe(struct auxiliary_device *adev,
 	const struct of_device_id *match;
 	struct qcom_battmgr *battmgr;
 	struct device *dev = &adev->dev;
+	int ret;
 
 	battmgr = devm_kzalloc(dev, sizeof(*battmgr), GFP_KERNEL);
 	if (!battmgr)
@@ -1344,7 +1346,6 @@ 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);
 
@@ -1391,6 +1392,11 @@ 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,
-- 
2.53.0