This is a note to let you know that I've just added the patch titled
USB: serial: fix null-pointer dereferences on disconnect
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From b2ca699076573c94fee9a73cb0d8645383b602a0 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Wed, 13 Feb 2013 17:53:28 +0100
Subject: 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 <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/serial/ftdi_sio.c | 20 +++++++++-----------
drivers/usb/serial/mct_u232.c | 22 +++++++++-------------
drivers/usb/serial/quatech2.c | 18 ++++++++----------
drivers/usb/serial/sierra.c | 8 +-------
drivers/usb/serial/ssu100.c | 19 ++++++++-----------
drivers/usb/serial/usb-serial.c | 14 ++++++++++++--
drivers/usb/serial/usb_wwan.c | 8 +++-----
7 files changed, 50 insertions(+), 59 deletions(-)
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 90ceef1..d07fccf 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1886,24 +1886,22 @@ static void ftdi_dtr_rts(struct usb_serial_port *port,
int on)
{
struct ftdi_private *priv = usb_get_serial_port_data(port);
- mutex_lock(&port->serial->disc_mutex);
- if (!port->serial->disconnected) {
- /* Disable flow control */
- if (!on && usb_control_msg(port->serial->dev,
+ /* Disable flow control */
+ if (!on) {
+ if (usb_control_msg(port->serial->dev,
usb_sndctrlpipe(port->serial->dev, 0),
FTDI_SIO_SET_FLOW_CTRL_REQUEST,
FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
0, priv->interface, NULL, 0,
WDR_TIMEOUT) < 0) {
- dev_err(&port->dev, "error from flowcontrol urb\n");
+ dev_err(&port->dev, "error from flowcontrol urb\n");
}
- /* drop RTS and DTR */
- if (on)
- set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
- else
- clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
}
- mutex_unlock(&port->serial->disc_mutex);
+ /* drop RTS and DTR */
+ if (on)
+ set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
+ else
+ clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
}
/*
diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index b691175..d9c8651 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -499,19 +499,15 @@ static void mct_u232_dtr_rts(struct usb_serial_port
*port, int on)
unsigned int control_state;
struct mct_u232_private *priv = usb_get_serial_port_data(port);
- mutex_lock(&port->serial->disc_mutex);
- if (!port->serial->disconnected) {
- /* drop DTR and RTS */
- spin_lock_irq(&priv->lock);
- if (on)
- priv->control_state |= TIOCM_DTR | TIOCM_RTS;
- else
- priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
- control_state = priv->control_state;
- spin_unlock_irq(&priv->lock);
- mct_u232_set_modem_ctrl(port, control_state);
- }
- mutex_unlock(&port->serial->disc_mutex);
+ spin_lock_irq(&priv->lock);
+ if (on)
+ priv->control_state |= TIOCM_DTR | TIOCM_RTS;
+ else
+ priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
+ control_state = priv->control_state;
+ spin_unlock_irq(&priv->lock);
+
+ mct_u232_set_modem_ctrl(port, control_state);
}
static void mct_u232_close(struct usb_serial_port *port)
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c
index d152be9..a8d5110 100644
--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -945,19 +945,17 @@ static void qt2_dtr_rts(struct usb_serial_port *port, int
on)
struct usb_device *dev = port->serial->dev;
struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
- mutex_lock(&port->serial->disc_mutex);
- if (!port->serial->disconnected) {
- /* Disable flow control */
- if (!on && qt2_setregister(dev, port_priv->device_port,
+ /* Disable flow control */
+ if (!on) {
+ if (qt2_setregister(dev, port_priv->device_port,
UART_MCR, 0) < 0)
dev_warn(&port->dev, "error from flowcontrol urb\n");
- /* drop RTS and DTR */
- if (on)
- update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
- else
- update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
}
- mutex_unlock(&port->serial->disc_mutex);
+ /* drop RTS and DTR */
+ if (on)
+ update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
+ else
+ update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
}
static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index af06f2f..d4426c0 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -861,19 +861,13 @@ 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)
diff --git a/drivers/usb/serial/ssu100.c b/drivers/usb/serial/ssu100.c
index 4543ea3..d938396 100644
--- a/drivers/usb/serial/ssu100.c
+++ b/drivers/usb/serial/ssu100.c
@@ -506,19 +506,16 @@ static void ssu100_dtr_rts(struct usb_serial_port *port,
int on)
{
struct usb_device *dev = port->serial->dev;
- mutex_lock(&port->serial->disc_mutex);
- if (!port->serial->disconnected) {
- /* Disable flow control */
- if (!on &&
- ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
+ /* Disable flow control */
+ if (!on) {
+ if (ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
dev_err(&port->dev, "error from flowcontrol urb\n");
- /* drop RTS and DTR */
- if (on)
- set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
- else
- clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
}
- mutex_unlock(&port->serial->disc_mutex);
+ /* drop RTS and DTR */
+ if (on)
+ set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
+ else
+ clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
}
static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 0a17f59..a19ed74 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -694,10 +694,20 @@ static int serial_carrier_raised(struct tty_port *port)
static void serial_dtr_rts(struct tty_port *port, int on)
{
struct usb_serial_port *p = container_of(port, struct usb_serial_port,
port);
- struct usb_serial_driver *drv = p->serial->type;
+ struct usb_serial *serial = p->serial;
+ struct usb_serial_driver *drv = serial->type;
- if (drv->dtr_rts)
+ if (!drv->dtr_rts)
+ return;
+ /*
+ * Work-around bug in the tty-layer which can result in dtr_rts
+ * being called after a disconnect (and tty_unregister_device
+ * has returned). Remove once bug has been squashed.
+ */
+ mutex_lock(&serial->disc_mutex);
+ if (!serial->disconnected)
drv->dtr_rts(p, on);
+ mutex_unlock(&serial->disc_mutex);
}
static const struct tty_port_operations serial_port_ops = {
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c
index 01c94aa..1355a6c 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);
--
1.8.1.rc1.5.g7e0651a
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