[3.19.y-ckt stable] Patch "iio: adis_buffer: Fix out-of-bounds memory access" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

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

    iio: adis_buffer: Fix out-of-bounds memory access

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt15.

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

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 5183301207ce2e92fd776629d63a5586ee168f24 Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars at metafoo.de>
Date: Fri, 27 Nov 2015 14:55:56 +0100
Subject: iio: adis_buffer: Fix out-of-bounds memory access

commit d590faf9e8f8509a0a0aa79c38e87fcc6b913248 upstream.

The SPI tx and rx buffers are both supposed to be scan_bytes amount of
bytes large and a common allocation is used to allocate both buffers. This
puts the beginning of the tx buffer scan_bytes bytes after the rx buffer.
The initialization of the tx buffer pointer is done adding scan_bytes to
the beginning of the rx buffer, but since the rx buffer is of type __be16
this will actually add two times as much and the tx buffer ends up pointing
after the allocated buffer.

Fix this by using scan_count, which is scan_bytes / 2, instead of
scan_bytes when initializing the tx buffer pointer.

Fixes: aacff892cbd5 ("staging:iio:adis: Preallocate transfer message")
Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/iio/imu/adis_buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/imu/adis_buffer.c b/drivers/iio/imu/adis_buffer.c
index cb32b59..36607d5 100644
--- a/drivers/iio/imu/adis_buffer.c
+++ b/drivers/iio/imu/adis_buffer.c
@@ -43,7 +43,7 @@ int adis_update_scan_mode(struct iio_dev *indio_dev,
 		return -ENOMEM;

 	rx = adis->buffer;
-	tx = rx + indio_dev->scan_bytes;
+	tx = rx + scan_count;

 	spi_message_init(&adis->msg);

--
1.9.1