From 49fbb8e37a961396a5b6c82937c70df91de45e9d Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Sun, 25 Oct 2020 18:45:51 +0100
Subject: [PATCH] USB: serial: keyspan_pda: fix tx-unthrottle use-after-free
Git-commit: 49fbb8e37a961396a5b6c82937c70df91de45e9d
Patch-mainline: v5.11-rc1
References: git-fixes

The driver's transmit-unthrottle work was never flushed on disconnect,
something which could lead to the driver port data being freed while the
unthrottle work is still scheduled.

Fix this by cancelling the unthrottle work when shutting down the port.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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/keyspan_pda.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index d91180ab5f3b..781b6723379f 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -647,8 +647,12 @@ static int keyspan_pda_open(struct tty_struct *tty,
 }
 static void keyspan_pda_close(struct usb_serial_port *port)
 {
+	struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
+
 	usb_kill_urb(port->write_urb);
 	usb_kill_urb(port->interrupt_in_urb);
+
+	cancel_work_sync(&priv->unthrottle_work);
 }
 
 
-- 
2.26.2