[PATCH] Input: zforce - don't overwrite the stack

From: Oleksij Rempel <redacted>

If we get a corrupted packet with PAYLOAD_LENGTH > FRAME_MAXSIZE, we
will silently overwrite the stack.

Signed-off-by: Oleksij Rempel <redacted>
Signed-off-by: Dirk Behme <redacted>
---
 drivers/input/touchscreen/zforce_ts.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/zforce_ts.c b/drivers/input/touchscreen/zforce_ts.c
index c4cffcf..32749db 100644
--- a/drivers/input/touchscreen/zforce_ts.c
+++ b/drivers/input/touchscreen/zforce_ts.c

@@ -441,7 +441,7 @@ static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
 		goto unlock;
 	}
 
-	if (buf[PAYLOAD_LENGTH] == 0) {
+	if (buf[PAYLOAD_LENGTH] == 0 || buf[PAYLOAD_LENGTH] > FRAME_MAXSIZE) {
 		dev_err(&client->dev, "invalid payload length: %d\n",
 			buf[PAYLOAD_LENGTH]);
 		ret = -EIO;

-- 
2.3.4