From b87c6e86dac1bb5222279cc8ff7e09529e1c4ed9 Mon Sep 17 00:00:00 2001 From: Elina Pasheva Date: Mon, 15 Feb 2010 14:50:14 -0800 Subject: [PATCH] USB: serial: sierra driver indat_callback fix A crash has been reported with sierra driver on disconnect with Ubuntu/Lucid distribution based on kernel-2.6.32. The cause of the crash was determined as "NULL tty pointer was being referenced" and the NULL pointer was passed by sierra_indat_callback(). This patch modifies sierra_indat_callback() function to check for NULL tty structure pointer. This modification prevents a crash from happening when the device is disconnected. This patch fixes the bug reported in Launchpad: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/511157 Signed-off-by: Elina Pasheva Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/sierra.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c index 6aeea40081c2..fcec46603558 100644 --- a/drivers/usb/serial/sierra.c +++ b/drivers/usb/serial/sierra.c @@ -594,14 +594,17 @@ static void sierra_indat_callback(struct urb *urb) } else { if (urb->actual_length) { tty = tty_port_tty_get(&port->port); - - tty_buffer_request_room(tty, urb->actual_length); - tty_insert_flip_string(tty, data, urb->actual_length); - tty_flip_buffer_push(tty); - - tty_kref_put(tty); - usb_serial_debug_data(debug, &port->dev, __func__, - urb->actual_length, data); + if (tty) { + tty_buffer_request_room(tty, + urb->actual_length); + tty_insert_flip_string(tty, data, + urb->actual_length); + tty_flip_buffer_push(tty); + + tty_kref_put(tty); + usb_serial_debug_data(debug, &port->dev, + __func__, urb->actual_length, data); + } } else { dev_dbg(&port->dev, "%s: empty read urb" " received\n", __func__); -- 2.20.1