From ff82fc3a4a1d417dee1229681cc5285986edb1fa Mon Sep 17 00:00:00 2001 From: Ridham Khurana Date: Wed, 23 Sep 2026 11:39:02 +0000 Subject: [PATCH 1/3] gpio: xilinx: fix runtime PM leak on request error path pm_runtime_get_sync() leaves the usage counter incremented even when it fails, and xgpio_request() returns the error without dropping it. gpiolib does not call ->free() when ->request() fails, so xgpio_free(), which holds the only matching pm_runtime_put(), never runs. The reference is leaked and the controller can no longer runtime-suspend, so its clock stays enabled. Switch to pm_runtime_resume_and_get(), which only increments the usage counter on success. Fixes: 26b04774621e ("gpio: gpio-xilinx: Add support for suspend and resume") Cc: stable@vger.kernel.org Signed-off-by: Ridham Khurana Link: https://patch.msgid.link/20260923113905.1409290-1-khurana.ridham222@gmail.com Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-xilinx.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c index 532205175827..9406ce85f933 100644 --- a/drivers/gpio/gpio-xilinx.c +++ b/drivers/gpio/gpio-xilinx.c @@ -271,14 +271,7 @@ static void xgpio_save_regs(struct xgpio_instance *chip) static int xgpio_request(struct gpio_chip *chip, unsigned int offset) { - int ret; - - ret = pm_runtime_get_sync(chip->parent); - /* - * If the device is already active pm_runtime_get() will return 1 on - * success, but gpio_request still needs to return 0. - */ - return ret < 0 ? ret : 0; + return pm_runtime_resume_and_get(chip->parent); } static void xgpio_free(struct gpio_chip *chip, unsigned int offset) From 4d69e74034b208588636ecc177e0dd43a7696af3 Mon Sep 17 00:00:00 2001 From: Sang-Hoon Choi Date: Wed, 30 Sep 2026 02:37:31 +0900 Subject: [PATCH 2/3] gpio: exar: initialize the ID before registering its cleanup devm_add_action_or_reset() invokes the cleanup action immediately when registering the action fails. gpio_exar_probe() currently stores the allocated ID in exar_gpio only after registering the action, so that failure makes exar_devm_ida_free() release ID 0. If the allocated ID is nonzero, this leaks that ID and can free ID 0 belonging to another device. Store the ID before registering the cleanup action so both the immediate failure path and normal device teardown release the correct allocation. Fixes: 5300ebb695fa ("gpio: exar: use devm action for freeing the IDA and drop remove()") Reported-by: Changyul Lee Assisted-by: LLM Signed-off-by: Sang-Hoon Choi Reviewed-by: Linus Walleij Link: https://patch.msgid.link/179070265834.12871.48183786512201899.idr-bug-79@gmail.com Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-exar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c index 9053662f1817..f629cc526f3e 100644 --- a/drivers/gpio/gpio-exar.c +++ b/drivers/gpio/gpio-exar.c @@ -199,6 +199,7 @@ static int gpio_exar_probe(struct platform_device *pdev) index = ida_alloc(&ida_index, GFP_KERNEL); if (index < 0) return index; + exar_gpio->index = index; ret = devm_add_action_or_reset(dev, exar_devm_ida_free, exar_gpio); if (ret) @@ -214,7 +215,6 @@ static int gpio_exar_probe(struct platform_device *pdev) exar_gpio->gpio_chip.set = exar_set_value; exar_gpio->gpio_chip.base = -1; exar_gpio->gpio_chip.ngpio = ngpios; - exar_gpio->index = index; exar_gpio->first_pin = first_pin; ret = devm_gpiochip_add_data(dev, &exar_gpio->gpio_chip, exar_gpio); From 7efa1a1953cd6b20b23a3524d5b4b81789c6ef25 Mon Sep 17 00:00:00 2001 From: Fan Wu Date: Tue, 29 Sep 2026 09:36:46 +0000 Subject: [PATCH 3/3] gpio: mpsse: fix race when arming the IRQ poll worker gpio_mpsse_irq_enable() arms the poll worker before publishing it: schedule_work() runs before the worker is added to priv->workers. If gpio_mpsse_disconnect() walks the list in that window it misses the worker, and once disconnect returns, the USB core frees mpsse_priv while the orphaned gpio_mpsse_poll() work keeps accessing it, causing a use-after-free. Fix this by publishing and arming the worker in one irq_spin critical section. Teardown walks the same list under irq_spin, so a worker found on the list is guaranteed to be armed, and cancel_work_sync() handles it whether it is queued or running. A worker armed after the disconnect walk would still be missed, so also set a new priv->dying flag under irq_spin before the teardown walk, and check it in the same critical section, freeing it via kfree_rcu() instead when the device is going away, since kfree() would be called with the IRQ core's raw spinlock held and may sleep on PREEMPT_RT. schedule_work() is safe to call with irq_spin held, and the next probe gets a fresh mpsse_priv, so the flag never needs to be cleared. This issue was found by an in-house static analysis tool. Fixes: 179ef1127d7a ("gpio: mpsse: ensure worker is torn down") Cc: stable@vger.kernel.org Co-developed-by: Song Li Signed-off-by: Song Li Signed-off-by: Fan Wu Link: https://patch.msgid.link/20260929093646.18419-1-fanwu01@zju.edu.cn Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-mpsse.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-mpsse.c b/drivers/gpio/gpio-mpsse.c index 30e8009b5fcc..61c5ca96314b 100644 --- a/drivers/gpio/gpio-mpsse.c +++ b/drivers/gpio/gpio-mpsse.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -24,6 +25,7 @@ struct mpsse_priv { raw_spinlock_t irq_spin; /* protects worker list */ atomic_t irq_type[16]; /* pin -> edge detection type */ atomic_t irq_enabled; + atomic_t dying; /* no new workers after disconnect */ int id; u8 gpio_outputs[2]; /* Output states for GPIOs [L, H] */ @@ -46,6 +48,7 @@ struct mpsse_worker { atomic_t cancelled; struct list_head list; /* linked list */ struct list_head destroy; /* teardown linked list */ + struct rcu_head rcu; /* deferred free for dying path */ }; struct bulk_desc { @@ -525,10 +528,24 @@ static void gpio_mpsse_irq_enable(struct irq_data *irqd) worker->priv = priv; INIT_LIST_HEAD(&worker->list); INIT_WORK(&worker->work, gpio_mpsse_poll); - schedule_work(&worker->work); - scoped_guard(raw_spinlock_irqsave, &priv->irq_spin) + scoped_guard(raw_spinlock_irqsave, &priv->irq_spin) { + if (atomic_read(&priv->dying)) { + /* + * Cannot kfree() here: this callback + * runs with the IRQ descriptor's raw + * spinlock held and kfree() may sleep + * on PREEMPT_RT. The worker is not + * yet published, so the deferred free + * is unobservable. + */ + kfree_rcu(worker, rcu); + return; + } + list_add(&worker->list, &priv->workers); + schedule_work(&worker->work); + } } } @@ -704,6 +721,9 @@ static void gpio_mpsse_disconnect(struct usb_interface *intf) { struct mpsse_priv *priv = usb_get_intfdata(intf); + scoped_guard(raw_spinlock_irqsave, &priv->irq_spin) + atomic_set(&priv->dying, 1); + /* * Lock prevents double-free of worker from here and the teardown * step at the beginning of gpio_mpsse_poll