From: Ricardo Ribalda Delgado Date: Fri, 3 Jun 2016 17:10:01 +0000 (+0200) Subject: gpiolib: Fix NULL pointer deference X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=11f33a6d15bfa397867ac0d7f3481b6dd683286f;p=openwrt%2Fstaging%2Fblogic.git gpiolib: Fix NULL pointer deference Under some circumstances, a gpiochip might be half cleaned from the gpio_device list. This patch makes sure that the chip pointer is still valid, before calling the match function. [ 104.088296] BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 [ 104.089772] IP: [] of_gpiochip_find_and_xlate+0x15/0x80 [ 104.128273] Call Trace: [ 104.129802] [] ? of_parse_own_gpio+0x1f0/0x1f0 [ 104.131353] [] gpiochip_find+0x60/0x90 [ 104.132868] [] of_get_named_gpiod_flags+0x9a/0x120 ... [ 104.141586] [] gpio_led_probe+0x11b/0x360 Cc: stable@vger.kernel.org Signed-off-by: Ricardo Ribalda Delgado Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 24f60d28f0c0..a2c31a5a677f 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -869,7 +869,7 @@ struct gpio_chip *gpiochip_find(void *data, spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) - if (match(gdev->chip, data)) + if (gdev->chip && match(gdev->chip, data)) break; /* No match? */