From 43018528944fa4965a4048fee91d76b47dcaf60e Mon Sep 17 00:00:00 2001
From: Laura Abbott <labbott@fedoraproject.org>
Date: Mon, 28 Sep 2015 14:10:34 -0700
Subject: [PATCH 1/2] si2168: Bounds check firmware
To: Antti Palosaari <crope@iki.fi>
To: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Olli Salonen <olli.salonen@iki.fi>
Cc: linux-media@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Stuart Auchterlonie <sauchter@redhat.com>
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.
Cc: stable@kernel.org
Reported-by: Stuart Auchterlonie <sauchter@redhat.com>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
---
drivers/media/dvb-frontends/si2168.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
index 81788c5..821a8f4 100644
--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -502,6 +502,10 @@ static int si2168_init(struct dvb_frontend *fe)
/* 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;
--
2.4.3