From: Johan Hovold johan@kernel.org
commit 9715a43eea77e42678a1002623f2d9a78f5b81a1 upstream.
Check for NULL port data in the modem- and line-status handlers to avoid dereferencing a NULL pointer in the unlikely case where a port device isn't bound to a driver (e.g. after an allocation failure on port probe).
Note that the other (stubbed) event handlers qt2_process_xmit_empty() and qt2_process_flush() would need similar sanity checks in case they are ever implemented.
Fixes: f7a33e608d9a ("USB: serial: add quatech2 usb to serial driver") Cc: stable stable@vger.kernel.org # 3.5 Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/usb/serial/quatech2.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c index b61c2a9..9ae57a9 100644 --- a/drivers/usb/serial/quatech2.c +++ b/drivers/usb/serial/quatech2.c @@ -864,7 +864,10 @@ static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch) u8 newMSR = (u8) *ch; unsigned long flags;
+ /* May be called from qt2_process_read_urb() for an unbound port. */ port_priv = usb_get_serial_port_data(port); + if (!port_priv) + return;
spin_lock_irqsave(&port_priv->lock, flags); port_priv->shadowMSR = newMSR; @@ -892,7 +895,10 @@ static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch) unsigned long flags; u8 newLSR = (u8) *ch;
+ /* May be called from qt2_process_read_urb() for an unbound port. */ port_priv = usb_get_serial_port_data(port); + if (!port_priv) + return;
if (newLSR & UART_LSR_BI) newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);