| From f0ac112a640063ba802d588adc21176beb44d579 Mon Sep 17 00:00:00 2001 |
| From: Johan Hovold <johan@kernel.org> |
| Date: Fri, 17 Jan 2020 15:35:26 +0100 |
| Subject: [PATCH] USB: serial: quatech2: handle unbound ports |
| |
| 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: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c |
| index a62981ca7a73..f93b81a297d6 100644 |
| --- a/drivers/usb/serial/quatech2.c |
| +++ b/drivers/usb/serial/quatech2.c |
| @@ -841,7 +841,10 @@ 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; |
| @@ -869,7 +872,10 @@ 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); |
| -- |
| 2.7.4 |
| |
