diff options
| author | Johan Hovold <jhovold@gmail.com> | 2013-02-13 17:53:28 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-02-13 18:20:06 +0100 |
| commit | b2ca699076573c94fee9a73cb0d8645383b602a0 (patch) | |
| tree | b9579ce8ed1511a5b3a234b03392b3c095de9231 /drivers/usb/serial/usb_wwan.c | |
| parent | USB: option: add Yota / Megafon M100-1 4g modem (diff) | |
| download | linux-b2ca699076573c94fee9a73cb0d8645383b602a0.tar.xz linux-b2ca699076573c94fee9a73cb0d8645383b602a0.zip | |
USB: serial: fix null-pointer dereferences on disconnect
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>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/serial/usb_wwan.c')
| -rw-r--r-- | drivers/usb/serial/usb_wwan.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c index 01c94aada56c..1355a6cd4508 100644 --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -38,7 +38,6 @@ void usb_wwan_dtr_rts(struct usb_serial_port *port, int on) { - struct usb_serial *serial = port->serial; struct usb_wwan_port_private *portdata; struct usb_wwan_intf_private *intfdata; @@ -48,12 +47,11 @@ void usb_wwan_dtr_rts(struct usb_serial_port *port, int on) return; portdata = usb_get_serial_port_data(port); - mutex_lock(&serial->disc_mutex); + /* FIXME: locking */ portdata->rts_state = on; portdata->dtr_state = on; - if (serial->dev) - intfdata->send_setup(port); - mutex_unlock(&serial->disc_mutex); + + intfdata->send_setup(port); } EXPORT_SYMBOL(usb_wwan_dtr_rts); |