3.2.89-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Johan Hovold <johan@xxxxxxxxxx>
commit c528fcb116e61afc379a2e0a0f70906b937f1e2c upstream.
Make sure to check for short transfers before parsing the receive buffer
to avoid acting on stale data.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
[bwh: Backported to 3.2:
- Adjust context
- Keep the check for !tty in the data case]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/serial/keyspan_pda.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -212,6 +212,7 @@ static void keyspan_pda_rx_interrupt(str
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(str
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 */