From ad83fa5a15a6a394718ae4034a44d58904acabd1 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 1 Mar 2021 10:05:19 +0100 Subject: [PATCH] gpio: fix gpio-device list corruption commit cf25ef6b631c6fc6c0435fc91eba8734cca20511 upstream. Make sure to hold the gpio_lock when removing the gpio device from the gpio_devices list (when dropping the last reference) to avoid corrupting the list when there are concurrent accesses. Fixes: ff2b13592299 ("gpio: make the gpiochip a real device") Cc: stable@vger.kernel.org # 4.6 Reviewed-by: Saravana Kannan Signed-off-by: Johan Hovold Signed-off-by: Bartosz Golaszewski [ johan: adjust context to 5.11 ] Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/gpio/gpiolib.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 97eec8d8dbdc4..e4cfa27f6893d 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -473,8 +473,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = dev_get_drvdata(dev); + unsigned long flags; + spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); + spin_unlock_irqrestore(&gpio_lock, flags); + ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); kfree(gdev->descs);