From: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
To: Linus Walleij <linus.walleij@linaro.org>,
Alexandre Courbot <gnurou@gmail.com>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Subject: [PATCH 1/2] gpiolib: Fix NULL pointer deference
Date: Fri, 3 Jun 2016 19:10:01 +0200 [thread overview]
Message-ID: <1464973802-9286-1-git-send-email-ricardo.ribalda@gmail.com> (raw)
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@gmail.com>
---
We might want to cc: stable on these two patches
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 d407f904a31c..0626cc96744b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -858,7 +858,7 @@ 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? */
--
2.8.1
next reply other threads:[~2016-06-03 17:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-03 17:10 Ricardo Ribalda Delgado [this message]
2016-06-03 17:10 ` [PATCH 2/2] gpiolib: Fix unaligned used of reference counters Ricardo Ribalda Delgado
2016-06-08 8:41 ` Linus Walleij
2016-06-08 8:39 ` [PATCH 1/2] gpiolib: Fix NULL pointer deference Linus Walleij
2016-06-08 9:46 ` Grygorii Strashko
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