From 49ceae35b608fbbc36e7e2a6c9bf84ce69ff5fb4 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 16 Apr 2020 12:09:27 +0800 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 # 3.5 Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- 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 b61c2a9b6b11..9ae57a961027 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); -- GitLab