diff options
| author | Johan Hovold <jhovold@gmail.com> | 2013-02-13 17:53:28 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-03-06 03:23:57 +0000 |
| commit | 36614259f65555c6194d8d5dcd554a1ded0458a5 (patch) | |
| tree | 414185802139a7939a6e8399e7a3a5a8ea519005 /drivers/usb/serial/sierra.c | |
| parent | 0055ccfc4019801fda4800c468232344dc7af316 (diff) | |
USB: serial: fix null-pointer dereferences on disconnect
commit b2ca699076573c94fee9a73cb0d8645383b602a0 upstream.
Make sure serial-driver dtr_rts is called with disc_mutex held after
checking the disconnected flag.
Due to a bug in the tty layer, dtr_rts may get called after a device has
been disconnected and the tty-device unregistered. Some drivers have had
individual checks for disconnect to make sure the disconnected interface
was not accessed, but this should really be handled in usb-serial core
(at least until the long-standing tty-bug has been fixed).
Note that the problem has been made more acute with commit 0998d0631001
("device-core: Ensure drvdata = NULL when no driver is bound") as the
port data is now also NULL when dtr_rts is called resulting in further
oopses.
Reported-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
- Adjust context
- Drop changes to quatech2.c]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/usb/serial/sierra.c')
| -rw-r--r-- | drivers/usb/serial/sierra.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c index e1f1ebda5f45..a7fa673466ce 100644 --- a/drivers/usb/serial/sierra.c +++ b/drivers/usb/serial/sierra.c @@ -891,19 +891,13 @@ static int sierra_open(struct tty_struct *tty, struct usb_serial_port *port) static void sierra_dtr_rts(struct usb_serial_port *port, int on) { - struct usb_serial *serial = port->serial; struct sierra_port_private *portdata; portdata = usb_get_serial_port_data(port); portdata->rts_state = on; portdata->dtr_state = on; - if (serial->dev) { - mutex_lock(&serial->disc_mutex); - if (!serial->disconnected) - sierra_send_setup(port); - mutex_unlock(&serial->disc_mutex); - } + sierra_send_setup(port); } static int sierra_startup(struct usb_serial *serial) |