Commit b9d711c4 authored by Johan Hovold's avatar Johan Hovold Committed by Ben Hutchings

USB: serial: keyspan_pda: fix receive sanity checks

commit c528fcb1 upstream.

Make sure to check for short transfers before parsing the receive buffer
to avoid acting on stale data.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
[bwh: Backported to 3.2:
 - Adjust context
 - Keep the check for !tty in the data case]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent 0ec74596
......@@ -212,6 +212,7 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
struct usb_serial_port *port = urb->context;
struct tty_struct *tty;
unsigned char *data = urb->transfer_buffer;
unsigned int len = urb->actual_length;
int retval;
int status = urb->status;
struct keyspan_pda_private *priv;
......@@ -234,20 +235,28 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
goto exit;
}
if (len < 1) {
dev_warn(&port->dev, "short message received\n");
goto exit;
}
/* see if the message is data or a status interrupt */
switch (data[0]) {
case 0:
tty = tty_port_tty_get(&port->port);
/* rest of message is rx data */
if (tty && urb->actual_length) {
tty_insert_flip_string(tty, data + 1,
urb->actual_length - 1);
tty_flip_buffer_push(tty);
}
if (!tty || len < 2)
break;
tty_insert_flip_string(tty, data + 1, len - 1);
tty_flip_buffer_push(tty);
tty_kref_put(tty);
break;
case 1:
/* status interrupt */
if (len < 3) {
dev_warn(&port->dev, "short interrupt message received\n");
break;
}
dbg(" rx int, d1=%d, d2=%d", data[1], data[2]);
switch (data[1]) {
case 1: /* modemline change */
......
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