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 0998d06310
("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>
This commit is contained in:
parent
cd565279e5
commit
b2ca699076
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@ -1886,24 +1886,22 @@ static void ftdi_dtr_rts(struct usb_serial_port *port, int on)
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{
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struct ftdi_private *priv = usb_get_serial_port_data(port);
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mutex_lock(&port->serial->disc_mutex);
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if (!port->serial->disconnected) {
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/* Disable flow control */
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if (!on && usb_control_msg(port->serial->dev,
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/* Disable flow control */
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if (!on) {
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if (usb_control_msg(port->serial->dev,
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usb_sndctrlpipe(port->serial->dev, 0),
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FTDI_SIO_SET_FLOW_CTRL_REQUEST,
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FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
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0, priv->interface, NULL, 0,
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WDR_TIMEOUT) < 0) {
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dev_err(&port->dev, "error from flowcontrol urb\n");
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dev_err(&port->dev, "error from flowcontrol urb\n");
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}
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/* drop RTS and DTR */
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if (on)
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set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
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else
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clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
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}
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mutex_unlock(&port->serial->disc_mutex);
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/* drop RTS and DTR */
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if (on)
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set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
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else
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clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
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}
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/*
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@ -499,19 +499,15 @@ static void mct_u232_dtr_rts(struct usb_serial_port *port, int on)
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unsigned int control_state;
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struct mct_u232_private *priv = usb_get_serial_port_data(port);
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mutex_lock(&port->serial->disc_mutex);
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if (!port->serial->disconnected) {
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/* drop DTR and RTS */
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spin_lock_irq(&priv->lock);
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if (on)
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priv->control_state |= TIOCM_DTR | TIOCM_RTS;
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else
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priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
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control_state = priv->control_state;
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spin_unlock_irq(&priv->lock);
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mct_u232_set_modem_ctrl(port, control_state);
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}
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mutex_unlock(&port->serial->disc_mutex);
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spin_lock_irq(&priv->lock);
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if (on)
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priv->control_state |= TIOCM_DTR | TIOCM_RTS;
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else
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priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
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control_state = priv->control_state;
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spin_unlock_irq(&priv->lock);
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mct_u232_set_modem_ctrl(port, control_state);
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}
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static void mct_u232_close(struct usb_serial_port *port)
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@ -945,19 +945,17 @@ static void qt2_dtr_rts(struct usb_serial_port *port, int on)
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struct usb_device *dev = port->serial->dev;
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struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
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mutex_lock(&port->serial->disc_mutex);
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if (!port->serial->disconnected) {
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/* Disable flow control */
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if (!on && qt2_setregister(dev, port_priv->device_port,
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/* Disable flow control */
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if (!on) {
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if (qt2_setregister(dev, port_priv->device_port,
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UART_MCR, 0) < 0)
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dev_warn(&port->dev, "error from flowcontrol urb\n");
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/* drop RTS and DTR */
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if (on)
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update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
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else
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update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
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}
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mutex_unlock(&port->serial->disc_mutex);
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/* drop RTS and DTR */
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if (on)
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update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
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else
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update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
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}
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static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
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@ -861,19 +861,13 @@ static int sierra_open(struct tty_struct *tty, struct usb_serial_port *port)
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static void sierra_dtr_rts(struct usb_serial_port *port, int on)
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{
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struct usb_serial *serial = port->serial;
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struct sierra_port_private *portdata;
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portdata = usb_get_serial_port_data(port);
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portdata->rts_state = on;
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portdata->dtr_state = on;
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if (serial->dev) {
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mutex_lock(&serial->disc_mutex);
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if (!serial->disconnected)
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sierra_send_setup(port);
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mutex_unlock(&serial->disc_mutex);
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}
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sierra_send_setup(port);
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}
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static int sierra_startup(struct usb_serial *serial)
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@ -506,19 +506,16 @@ static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
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{
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struct usb_device *dev = port->serial->dev;
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mutex_lock(&port->serial->disc_mutex);
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if (!port->serial->disconnected) {
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/* Disable flow control */
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if (!on &&
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ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
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/* Disable flow control */
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if (!on) {
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if (ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
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dev_err(&port->dev, "error from flowcontrol urb\n");
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/* drop RTS and DTR */
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if (on)
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set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
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else
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clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
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}
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mutex_unlock(&port->serial->disc_mutex);
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/* drop RTS and DTR */
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if (on)
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set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
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else
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clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
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}
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static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
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@ -694,10 +694,20 @@ static int serial_carrier_raised(struct tty_port *port)
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static void serial_dtr_rts(struct tty_port *port, int on)
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{
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struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
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struct usb_serial_driver *drv = p->serial->type;
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struct usb_serial *serial = p->serial;
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struct usb_serial_driver *drv = serial->type;
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if (drv->dtr_rts)
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if (!drv->dtr_rts)
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return;
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/*
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* Work-around bug in the tty-layer which can result in dtr_rts
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* being called after a disconnect (and tty_unregister_device
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* has returned). Remove once bug has been squashed.
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*/
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mutex_lock(&serial->disc_mutex);
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if (!serial->disconnected)
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drv->dtr_rts(p, on);
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mutex_unlock(&serial->disc_mutex);
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}
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static const struct tty_port_operations serial_port_ops = {
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@ -38,7 +38,6 @@
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void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
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{
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struct usb_serial *serial = port->serial;
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struct usb_wwan_port_private *portdata;
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struct usb_wwan_intf_private *intfdata;
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@ -48,12 +47,11 @@ void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
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return;
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portdata = usb_get_serial_port_data(port);
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mutex_lock(&serial->disc_mutex);
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/* FIXME: locking */
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portdata->rts_state = on;
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portdata->dtr_state = on;
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if (serial->dev)
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intfdata->send_setup(port);
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mutex_unlock(&serial->disc_mutex);
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intfdata->send_setup(port);
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}
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EXPORT_SYMBOL(usb_wwan_dtr_rts);
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