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")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/serial/keyspan_pda.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 83523fcf6fb9..d2dab2a341b8 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -139,6 +139,7 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
unsigned char *data = urb->transfer_buffer;
+ unsigned int len = urb->actual_length;
int retval;
int status = urb->status;
struct keyspan_pda_private *priv;
@@ -159,18 +160,26 @@ 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:
/* rest of message is rx data */
- if (urb->actual_length) {
- tty_insert_flip_string(&port->port, data + 1,
- urb->actual_length - 1);
- tty_flip_buffer_push(&port->port);
- }
+ if (len < 2)
+ break;
+ tty_insert_flip_string(&port->port, data + 1, len - 1);
+ tty_flip_buffer_push(&port->port);
break;
case 1:
/* status interrupt */
+ if (len < 3) {
+ dev_warn(&port->dev, "short interrupt message received\n");
+ break;
+ }
dev_dbg(&port->dev, "rx int, d1=%d, d2=%d\n", data[1], data[2]);
switch (data[1]) {
case 1: /* modemline change */
--
2.10.2
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