From: Ricardo Ribalda Delgado <redacted>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit 11f33a6d15bfa397867ac0d7f3481b6dd683286f ]
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
Cc: <redacted>
Signed-off-by: Ricardo Ribalda Delgado <redacted>
Signed-off-by: Linus Walleij <redacted>
Signed-off-by: Sasha Levin <redacted>
---
drivers/gpio/gpiolib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6bc612b..95752d3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -375,7 +375,7 @@ struct gpio_chip *gpiochip_find(void *data,
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(chip, &gpio_chips, list)
- if (match(chip, data))
+ if (chip && match(chip, data))
break;
/* No match? */
--
2.5.0