| Message ID | 20210301090519.26192-3-johan@kernel.org |
|---|---|
| State | Accepted |
| Commit | cf25ef6b631c6fc6c0435fc91eba8734cca20511 |
| Headers | show |
| Series | gpio: regression fixes | expand |
On Mon, Mar 1, 2021 at 10:05 AM Johan Hovold <johan@kernel.org> wrote: > 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 <saravanak@google.com> > Signed-off-by: Johan Hovold <johan@kernel.org> Excellent fix as well, Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 6e0572515d02..4253837f870b 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = container_of(dev, struct gpio_device, 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);
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 <saravanak@google.com> Signed-off-by: Johan Hovold <johan@kernel.org> --- drivers/gpio/gpiolib.c | 4 ++++ 1 file changed, 4 insertions(+)