From eb8878a881c306ff3eab6e741ab8fc94096f4e1a Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sat, 27 Feb 2010 16:24:49 +0100 Subject: USB: serial: use port endpoint size to determine if ep is available It is possible to have a multi-port device with a port lacking an in or out bulk endpoint. Only checking for num_bulk_in or num_bulk_out is thus not sufficient to determine whether a specific port has an in or out bulk endpoint. This fixes potential null pointer dereferences in the generic open and write routines, as well as access to uninitialised fifo in write_room and chars_in_buffer. Also let write fail with ENODEV (instead of 0) on missing out endpoint (also on zero-length writes). Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/generic.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) (limited to 'drivers/usb/serial/generic.c') diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 214bf25bc3b..f804acb138e 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -130,7 +130,7 @@ int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port spin_unlock_irqrestore(&port->lock, flags); /* if we have a bulk endpoint, start reading from it */ - if (serial->num_bulk_in) { + if (port->bulk_in_size) { /* Start reading from the device */ usb_fill_bulk_urb(port->read_urb, serial->dev, usb_rcvbulkpipe(serial->dev, @@ -159,10 +159,10 @@ static void generic_cleanup(struct usb_serial_port *port) dbg("%s - port %d", __func__, port->number); if (serial->dev) { - /* shutdown any bulk reads that might be going on */ - if (serial->num_bulk_out) + /* shutdown any bulk transfers that might be going on */ + if (port->bulk_out_size) usb_kill_urb(port->write_urb); - if (serial->num_bulk_in) + if (port->bulk_in_size) usb_kill_urb(port->read_urb); } } @@ -333,15 +333,15 @@ int usb_serial_generic_write(struct tty_struct *tty, dbg("%s - port %d", __func__, port->number); + /* only do something if we have a bulk out endpoint */ + if (!port->bulk_out_size) + return -ENODEV; + if (count == 0) { dbg("%s - write request of 0 bytes", __func__); return 0; } - /* only do something if we have a bulk out endpoint */ - if (!serial->num_bulk_out) - return 0; - if (serial->type->max_in_flight_urbs) return usb_serial_multi_urb_write(tty, port, buf, count); @@ -364,14 +364,19 @@ int usb_serial_generic_write_room(struct tty_struct *tty) int room = 0; dbg("%s - port %d", __func__, port->number); + + if (!port->bulk_out_size) + return 0; + spin_lock_irqsave(&port->lock, flags); if (serial->type->max_in_flight_urbs) { if (port->urbs_in_flight < serial->type->max_in_flight_urbs) room = port->bulk_out_size * (serial->type->max_in_flight_urbs - port->urbs_in_flight); - } else if (serial->num_bulk_out) + } else { room = kfifo_avail(&port->write_fifo); + } spin_unlock_irqrestore(&port->lock, flags); dbg("%s - returns %d", __func__, room); @@ -382,15 +387,18 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct usb_serial *serial = port->serial; - int chars = 0; unsigned long flags; + int chars; dbg("%s - port %d", __func__, port->number); + if (!port->bulk_out_size) + return 0; + spin_lock_irqsave(&port->lock, flags); if (serial->type->max_in_flight_urbs) chars = port->tx_bytes_flight; - else if (serial->num_bulk_out) + else chars = kfifo_len(&port->write_fifo); spin_unlock_irqrestore(&port->lock, flags); -- cgit v1.2.3-18-g5258