From a2471ed17b0e6ff7bfb6b2ea8e6e5b04c309d293 Mon Sep 17 00:00:00 2001 From: Fan Wu Date: Wed, 19 Aug 2026 03:33:17 +0000 Subject: [PATCH] hwmon: (gpio-fan) Fix use-after-free in alarm work fan_alarm_irq_handler() queues fan_data->alarm_work, but nothing cancels it. fan_alarm_notify() dereferences fan_data and its hwmon device. On unbind, devres frees the interrupt, which only waits for the handler itself, and then releases the hwmon device and fan_data, so a pending fan_alarm_notify() can run after those frees. Replace INIT_WORK() with devm_work_autocancel(), registered before devm_request_irq(). The devres cleanup then frees the interrupt first, so no new work can be queued, and cancels the work while fan_data and the hwmon device are still alive. This issue was found by an in-house static analysis tool. Fixes: d6fe1360f42e ("hwmon: add generic GPIO fan driver") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6 Signed-off-by: Fan Wu Link: https://patch.msgid.link/20260819033317.446191-1-fanwu01@zju.edu.cn Signed-off-by: Guenter Roeck --- drivers/hwmon/gpio-fan.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index 084828e1e281..7f36e5f6f223 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -84,6 +85,7 @@ static DEVICE_ATTR_RO(fan1_alarm); static int fan_alarm_init(struct gpio_fan_data *fan_data) { int alarm_irq; + int err; struct device *dev = fan_data->dev; /* @@ -94,7 +96,11 @@ static int fan_alarm_init(struct gpio_fan_data *fan_data) if (alarm_irq <= 0) return 0; - INIT_WORK(&fan_data->alarm_work, fan_alarm_notify); + err = devm_work_autocancel(dev, &fan_data->alarm_work, + fan_alarm_notify); + if (err) + return err; + irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH); return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler, IRQF_SHARED, "GPIO fan alarm", fan_data);