FAILED: patch "[PATCH] power: supply: qcom_battmgr: fix use-after-free" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-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 <[email protected]>.

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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 4e40befedfc8ed86f44e1f81df92d13c149c9f8d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090355-pretty-cube-4fda@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

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

From 4e40befedfc8ed86f44e1f81df92d13c149c9f8d Mon Sep 17 00:00:00 2001
From: Fan Wu <[email protected]>
Date: Sat, 1 Aug 2026 05:19:23 +0000
Subject: [PATCH] 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.

index c76389b2f7e8..91cf39b0083a 100644
@@ -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,

From: Fan Wu <[email protected]>

[ 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.

---
 drivers/power/supply/qcom_battmgr.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

index e5eade1328163..326cddfb8e347 100644
@@ -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