Patch "[media] si2168: Bounds check firmware" has been added to the 4.2-stable tree

Patch "[media] si2168: Bounds check firmware" has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    [media] si2168: Bounds check firmware

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     si2168-bounds-check-firmware.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 47810b4341ac9d2f558894bc5995e6fa2a1298f9 Mon Sep 17 00:00:00 2001
From: Laura Abbott <labbott@fedoraproject.org>
Date: Tue, 29 Sep 2015 21:10:09 -0300
Subject: [media] si2168: Bounds check firmware

From: Laura Abbott <labbott@fedoraproject.org>

commit 47810b4341ac9d2f558894bc5995e6fa2a1298f9 upstream.

When reading the firmware and sending commands, the length must
be bounds checked to avoid overrunning the size of the command
buffer and smashing the stack if the firmware is not in the expected
format:

si2168 11-0064: found a 'Silicon Labs Si2168-B40'
si2168 11-0064: downloading firmware from file 'dvb-demod-si2168-b40-01.fw'
si2168 11-0064: firmware download failed -95
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffffa085708f

Add the proper check.

Reported-by: Stuart Auchterlonie <sauchter@redhat.com>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/media/dvb-frontends/si2168.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -502,6 +502,10 @@ static int si2168_init(struct dvb_fronte
 		/* firmware is in the new format */
 		for (remaining = fw->size; remaining > 0; remaining -= 17) {
 			len = fw->data[fw->size - remaining];
+			if (len > SI2168_ARGLEN) {
+				ret = -EINVAL;
+				break;
+			}
 			memcpy(cmd.args, &fw->data[(fw->size - remaining) + 1], len);
 			cmd.wlen = len;
 			cmd.rlen = 1;


Patches currently in stable-queue which might be from labbott@fedoraproject.org are

queue-4.2/si2157-bounds-check-firmware.patch
queue-4.2/si2168-bounds-check-firmware.patch