From 4d5ef53f75c22d28f490bcc5c771fcc610a9afa4 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Fri, 17 Jan 2020 10:50:22 +0100
Subject: [PATCH] USB: serial: ch341: handle unbound port at reset_resume
Git-commit: 4d5ef53f75c22d28f490bcc5c771fcc610a9afa4
Patch-mainline: v5.5-rc7
References: bsc#1051510
Check for NULL port data in reset_resume() to avoid dereferencing a NULL
pointer in case the port device isn't bound to a driver (e.g. after a
failed control request at port probe).
Fixes: 1ded7ea47b88 ("USB: ch341 serial: fix port number changed after resume")
Cc: stable <stable@vger.kernel.org> # 2.6.30
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/usb/serial/ch341.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index df582fe855f0..d3f420f3a083 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -642,9 +642,13 @@ static int ch341_tiocmget(struct tty_struct *tty)
static int ch341_reset_resume(struct usb_serial *serial)
{
struct usb_serial_port *port = serial->port[0];
- struct ch341_private *priv = usb_get_serial_port_data(port);
+ struct ch341_private *priv;
int ret;
+ priv = usb_get_serial_port_data(port);
+ if (!priv)
+ return 0;
+
/* reconfigure ch341 serial port after bus-reset */
ch341_configure(serial->dev, priv);
--
2.16.4