[3.11.y.z extended stable] Patch "iio:imu:mpu6050: Fixed segfault in Invensens MPU driver due to null dereference" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    iio:imu:mpu6050: Fixed segfault in Invensens MPU driver due to null dereference

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From ed1d614c9cbf5a08f945d963ad3391f6a3cae530 Mon Sep 17 00:00:00 2001
From: Atilla Filiz <atilla.filiz at essensium.com>
Date: Fri, 11 Apr 2014 16:51:23 +0200
Subject: iio:imu:mpu6050: Fixed segfault in Invensens MPU driver due to null
 dereference

commit b9b3a41893c3f1be67b5aacfa525969914bea0e9 upstream.

The driver segfaults when the kernel boots with device tree as the
platform data is then not present and the pointer is deferenced without
checking it is not null.  This patch introduces such a check avoiding the
crash.

Signed-off-by: Atilla Filiz <atilla.filiz at essensium.com>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index fe4c61e..111ac38 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -660,6 +660,7 @@ static int inv_mpu_probe(struct i2c_client *client,
 {
 	struct inv_mpu6050_state *st;
 	struct iio_dev *indio_dev;
+	struct inv_mpu6050_platform_data *pdata;
 	int result;

 	if (!i2c_check_functionality(client->adapter,
@@ -675,8 +676,10 @@ static int inv_mpu_probe(struct i2c_client *client,
 	}
 	st = iio_priv(indio_dev);
 	st->client = client;
-	st->plat_data = *(struct inv_mpu6050_platform_data
-				*)dev_get_platdata(&client->dev);
+	pdata = (struct inv_mpu6050_platform_data
+			*)dev_get_platdata(&client->dev);
+	if (pdata)
+		st->plat_data = *pdata;
 	/* power is turned on inside check chip type*/
 	result = inv_check_and_setup_chip(st, id);
 	if (result)
--
1.9.1