Re: [PATCH 1/2] gpiolib: Fix NULL pointer deference

From: Grygorii Strashko
Date: Wed Jun 08 2016 - 05:46:53 EST


On 06/08/2016 11:39 AM, Linus Walleij wrote:
On Fri, Jun 3, 2016 at 7:10 PM, Ricardo Ribalda Delgado
<ricardo.ribalda@xxxxxxxxx> wrote:

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: [<ffffffff813d2045>] of_gpiochip_find_and_xlate+0x15/0x80
[ 104.128273] Call Trace:
[ 104.129802] [<ffffffff813d2030>] ? of_parse_own_gpio+0x1f0/0x1f0
[ 104.131353] [<ffffffff813cd910>] gpiochip_find+0x60/0x90
[ 104.132868] [<ffffffff813d21ba>] of_get_named_gpiod_flags+0x9a/0x120
...
[ 104.141586] [<ffffffff8163d12b>] gpio_led_probe+0x11b/0x360

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>

Oh there is the fix that Roger and Grygorii needs.

Applied to fixes and tagged for stable.

Sorry for screwing things up :(


Np. :)

--
regards,
-grygorii