[PATCH] usb: gadget: u_serial: Add null pointer check in gserial_resume

[Prashanth K]

Consider a case where gserial_disconnect has already cleared
gser->ioport. And if a wakeup interrupt triggers afterwards,
gserial_resume gets called, which will lead to accessing of
gserial->port and thus causing null pointer dereference.Add
a null pointer check to prevent this.

Fixes: aba3a8d01d62 (" usb: gadget: u_serial: add suspend resume callbacks")
Signed-off-by: Prashanth K <quic_prashk@xxxxxxxxxxx>
---
 drivers/usb/gadget/function/u_serial.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 840626e..98be2b8 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -1428,6 +1428,9 @@ void gserial_resume(struct gserial *gser)
 	struct gs_port *port = gser->ioport;
 	unsigned long	flags;
 
+	if (!port)
+		return;
+
 	spin_lock_irqsave(&port->port_lock, flags);
 	port->suspended = false;
 	if (!port->start_delayed) {
-- 
2.7.4