[PATCH 3.18 37/38] USB: serial: garmin_gps: fix I/O after failed probe and remove

Greg Kroah-Hartman
2017-11-19T15:18:25Z

From: Johan Hovold <johan@kernel.org>

commit 19a565d9af6e0d828bd0d521d3bafd5017f4ce52 upstream.

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")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/serial/garmin_gps.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

--- 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;
};

@@ -906,7 +907,7 @@ static int garmin_init_session(struct us
sizeof(GARMIN_START_SESSION_REQ), 0);

if (status < 0)
- break;
+ goto err_kill_urbs;
}

if (status > 0)
@@ -914,6 +915,12 @@ static int garmin_init_session(struct us
}

return status;
+
+err_kill_urbs:
+ usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
+ usb_kill_urb(port->interrupt_in_urb);
+
+ return status;
}

@@ -931,7 +938,6 @@ static int garmin_open(struct tty_struct
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)
@@ -954,7 +960,7 @@ static void garmin_close(struct usb_seri

/* 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)
@@ -1038,12 +1044,14 @@ static int garmin_write_bulk(struct usb_
}

/* 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);
}

@@ -1402,6 +1410,7 @@ static int garmin_port_probe(struct usb_
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);
@@ -1414,6 +1423,7 @@ static int garmin_port_remove(struct usb
{
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);