patch "USB: serial: garmin_gps: fix I/O after failed probe and remove" added to usb-next

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    USB: serial: garmin_gps: fix I/O after failed probe and remove

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release
during the merge window.

If you have any questions about this process, please let me know.


>From 19a565d9af6e0d828bd0d521d3bafd5017f4ce52 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 11 Oct 2017 14:02:57 +0200
Subject: USB: serial: garmin_gps: fix I/O after failed probe and remove

Make sure to stop any submitted interrupt and bulk-out URBs before
returning after failed probe and when the port is being unbound to avoid
later NULL-pointer dereferences in the completion callbacks.

Also fix up the related and broken I/O cancellation on failed open and
on close. (Note that port->write_urb was never submitted.)

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>	# 51a2f077 ("USB: introduce usb_anchor")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/garmin_gps.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/serial/garmin_gps.c b/drivers/usb/serial/garmin_gps.c
index 1f439b6e7e6f..8967de6623c4 100644
--- a/drivers/usb/serial/garmin_gps.c
+++ b/drivers/usb/serial/garmin_gps.c
@@ -138,6 +138,7 @@ struct garmin_data {
 	__u8   privpkt[4*6];
 	spinlock_t lock;
 	struct list_head pktlist;
+	struct usb_anchor write_urbs;
 };
 
 
@@ -905,13 +906,19 @@ static int garmin_init_session(struct usb_serial_port *port)
 					sizeof(GARMIN_START_SESSION_REQ), 0);
 
 			if (status < 0)
-				break;
+				goto err_kill_urbs;
 		}
 
 		if (status > 0)
 			status = 0;
 	}
 
+	return status;
+
+err_kill_urbs:
+	usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
+	usb_kill_urb(port->interrupt_in_urb);
+
 	return status;
 }
 
@@ -930,7 +937,6 @@ static int garmin_open(struct tty_struct *tty, struct usb_serial_port *port)
 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 
 	/* shutdown any bulk reads that might be going on */
-	usb_kill_urb(port->write_urb);
 	usb_kill_urb(port->read_urb);
 
 	if (garmin_data_p->state == STATE_RESET)
@@ -953,7 +959,7 @@ static void garmin_close(struct usb_serial_port *port)
 
 	/* shutdown our urbs */
 	usb_kill_urb(port->read_urb);
-	usb_kill_urb(port->write_urb);
+	usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
 
 	/* keep reset state so we know that we must start a new session */
 	if (garmin_data_p->state != STATE_RESET)
@@ -1037,12 +1043,14 @@ static int garmin_write_bulk(struct usb_serial_port *port,
 	}
 
 	/* send it down the pipe */
+	usb_anchor_urb(urb, &garmin_data_p->write_urbs);
 	status = usb_submit_urb(urb, GFP_ATOMIC);
 	if (status) {
 		dev_err(&port->dev,
 		   "%s - usb_submit_urb(write bulk) failed with status = %d\n",
 				__func__, status);
 		count = status;
+		usb_unanchor_urb(urb);
 		kfree(buffer);
 	}
 
@@ -1399,6 +1407,7 @@ static int garmin_port_probe(struct usb_serial_port *port)
 	garmin_data_p->state = 0;
 	garmin_data_p->flags = 0;
 	garmin_data_p->count = 0;
+	init_usb_anchor(&garmin_data_p->write_urbs);
 	usb_set_serial_port_data(port, garmin_data_p);
 
 	status = garmin_init_session(port);
@@ -1411,6 +1420,7 @@ static int garmin_port_remove(struct usb_serial_port *port)
 {
 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 
+	usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
 	usb_kill_urb(port->interrupt_in_urb);
 	del_timer_sync(&garmin_data_p->timer);
 	kfree(garmin_data_p);
-- 
2.15.0