Input: zforce - don't overwrite the stack

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

Cc: stable@vger.kernel.org
Signed-off-by: Oleksij Rempel <external.Oleksij.Rempel@de.bosch.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/zforce_ts.c b/drivers/input/touchscreen/zforce_ts.c
index f58a196..80285c7 100644 (file)
--- a/drivers/input/touchscreen/zforce_ts.c
+++ b/drivers/input/touchscreen/zforce_ts.c
@@ -429,7 +429,7 @@ 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;