From 526fbce5b0e44c67a97c57656b3be9911f0a9b9b Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 29 Sep 2015 16:59:20 -0700 Subject: [PATCH 2/2] si2157: Bounds check firmware To: Antti Palosaari To: Mauro Carvalho Chehab Cc: Olli Salonen Cc: linux-media@vger.kernel.org Cc: linux-kernel@vger.kernel.org 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. Add the proper check. Cc: stable@kernel.org Signed-off-by: Laura Abbott --- drivers/media/tuners/si2157.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/media/tuners/si2157.c b/drivers/media/tuners/si2157.c index 5073821..ce157ed 100644 --- a/drivers/media/tuners/si2157.c +++ b/drivers/media/tuners/si2157.c @@ -166,6 +166,10 @@ static int si2157_init(struct dvb_frontend *fe) for (remaining = fw->size; remaining > 0; remaining -= 17) { len = fw->data[fw->size - remaining]; + if (len > SI2157_ARGLEN) { + dev_err(&client->dev, "Bad firmware length\n"); + goto err_release_firmware; + } memcpy(cmd.args, &fw->data[(fw->size - remaining) + 1], len); cmd.wlen = len; cmd.rlen = 1; -- 2.4.3