From: Ma Ke <make24@iscas.ac.cn>
To: sre@kernel.org, philipp@uvos.xyz
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, Ma Ke <make24@iscas.ac.cn>,
stable@vger.kernel.org
Subject: [PATCH] power: supply: cpcap-battery: Fix missing nvmem_device_put() causing reference leak
Date: Fri, 24 Apr 2026 09:10:13 +0800 [thread overview]
Message-ID: <20260424011013.879639-1-make24@iscas.ac.cn> (raw)
In cpcap_battery_detect_battery_type(), the reference to an nvmem
device obtained via nvmem_device_find() is not released with
nvmem_device_put() on the success or read-failure paths, causing a
permanent reference leak. The driver’s retry logic on subsequent
battery property reads can compound this leak, preventing the nvmem
device from ever being freed.
Found by code review.
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
Cc: stable@vger.kernel.org
Fixes: fd46821e85de ("power: supply: cpcap-battery: Add battery type auto detection for mapphone devices")
---
drivers/power/supply/cpcap-battery.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
index 7b7bdce3162f..59c741993ef8 100644
--- a/drivers/power/supply/cpcap-battery.c
+++ b/drivers/power/supply/cpcap-battery.c
@@ -439,10 +439,13 @@ static void cpcap_battery_detect_battery_type(struct cpcap_battery_ddata *ddata)
if (IS_ERR_OR_NULL(nvmem)) {
ddata->check_nvmem = true;
dev_info_once(ddata->dev, "Can not find battery nvmem device. Assuming generic lipo battery\n");
- } else if (nvmem_device_read(nvmem, 2, 1, &battery_id) < 0) {
- battery_id = 0;
- ddata->check_nvmem = true;
- dev_warn(ddata->dev, "Can not read battery nvmem device. Assuming generic lipo battery\n");
+ } else {
+ if (nvmem_device_read(nvmem, 2, 1, &battery_id) < 0) {
+ battery_id = 0;
+ ddata->check_nvmem = true;
+ dev_warn(ddata->dev, "Can not read battery nvmem device. Assuming generic lipo battery\n");
+ }
+ nvmem_device_put(nvmem);
}
switch (battery_id) {
--
2.43.0
reply other threads:[~2026-04-24 1:16 UTC|newest]
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