[PATCH 2/2] si2157: Bounds check firmware

From	Laura Abbott <labbott@fedoraproject.org>
Newsgroups	linux.kernel
Subject	[PATCH 2/2] si2157: Bounds check firmware
Date	2015-09-30 02:20 +0200
Message-ID	<qedhM-5nT-5@gated-at.bofh.it> (permalink)
References	<qedhM-5nT-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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 <labbott@fedoraproject.org>
---
 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

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[PATCH 2/2] si2157: Bounds check firmware Laura Abbott <labbott@fedoraproject.org> - 2015-09-30 02:20 +0200

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