USB: serial: garmin_gps: add sanity checking for data length

We must not process packets shorter than a packet ID

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-and-tested-by: syzbot+d29e9263e13ce0b9f4fd@syzkaller.appspotmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/garmin_gps.c b/drivers/usb/serial/garmin_gps.c
index ffd9841..d63072f 100644 (file)
--- a/drivers/usb/serial/garmin_gps.c
+++ b/drivers/usb/serial/garmin_gps.c
@@ -1138,8 +1138,8 @@ static void garmin_read_process(struct garmin_data *garmin_data_p,
                   send it directly to the tty port */
                if (garmin_data_p->flags & FLAGS_QUEUING) {
                        pkt_add(garmin_data_p, data, data_length);
-               } else if (bulk_data ||
-                          getLayerId(data) == GARMIN_LAYERID_APPL) {
+               } else if (bulk_data || (data_length >= sizeof(u32) &&
+                               getLayerId(data) == GARMIN_LAYERID_APPL)) {
 
                        spin_lock_irqsave(&garmin_data_p->lock, flags);
                        garmin_data_p->flags |= APP_RESP_SEEN;