| From: Johan Hovold <johan@kernel.org> |
| Date: Fri, 17 Jan 2020 10:50:24 +0100 |
| Subject: USB: serial: io_edgeport: add missing active-port sanity check |
| |
| commit 1568c58d11a7c851bd09341aeefd6a1c308ac40d upstream. |
| |
| The driver receives the active port number from the device, but never |
| made sure that the port number was valid. This could lead to a |
| NULL-pointer dereference or memory corruption in case a device sends |
| data for an invalid port. |
| |
| Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") |
| Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| drivers/usb/serial/io_edgeport.c | 12 +++++++----- |
| 1 file changed, 7 insertions(+), 5 deletions(-) |
| |
| --- a/drivers/usb/serial/io_edgeport.c |
| +++ b/drivers/usb/serial/io_edgeport.c |
| @@ -1666,7 +1666,8 @@ static void edge_break(struct tty_struct |
| static void process_rcvd_data(struct edgeport_serial *edge_serial, |
| unsigned char *buffer, __u16 bufferLength) |
| { |
| - struct device *dev = &edge_serial->serial->dev->dev; |
| + struct usb_serial *serial = edge_serial->serial; |
| + struct device *dev = &serial->dev->dev; |
| struct usb_serial_port *port; |
| struct edgeport_port *edge_port; |
| __u16 lastBufferLength; |
| @@ -1771,9 +1772,8 @@ static void process_rcvd_data(struct edg |
| |
| /* spit this data back into the tty driver if this |
| port is open */ |
| - if (rxLen) { |
| - port = edge_serial->serial->port[ |
| - edge_serial->rxPort]; |
| + if (rxLen && edge_serial->rxPort < serial->num_ports) { |
| + port = serial->port[edge_serial->rxPort]; |
| edge_port = usb_get_serial_port_data(port); |
| if (edge_port && edge_port->open) { |
| dev_dbg(dev, "%s - Sending %d bytes to TTY for port %d\n", |
| @@ -1783,8 +1783,8 @@ static void process_rcvd_data(struct edg |
| rxLen); |
| edge_port->port->icount.rx += rxLen; |
| } |
| - buffer += rxLen; |
| } |
| + buffer += rxLen; |
| break; |
| |
| case EXPECT_HDR3: /* Expect 3rd byte of status header */ |
| @@ -1819,6 +1819,8 @@ static void process_rcvd_status(struct e |
| __u8 code = edge_serial->rxStatusCode; |
| |
| /* switch the port pointer to the one being currently talked about */ |
| + if (edge_serial->rxPort >= edge_serial->serial->num_ports) |
| + return; |
| port = edge_serial->serial->port[edge_serial->rxPort]; |
| edge_port = usb_get_serial_port_data(port); |
| if (edge_port == NULL) { |