[PATCH 3.2 05/79] USB: serial: garmin_gps: fix I/O after failed probe and remove

Ben Hutchings
2018-02-11T04:20:06Z

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: Ben Hutchings <ben@decadent.org.uk>
---
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
@@ -142,6 +142,7 @@ struct garmin_data {
__u8 privpkt[4*6];
spinlock_t lock;
struct list_head pktlist;
+ struct usb_anchor write_urbs;
};

@@ -923,7 +924,7 @@ static int garmin_init_session(struct us
sizeof(GARMIN_START_SESSION_REQ), 0);

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

if (status > 0)
@@ -931,6 +932,12 @@ 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;
}

@@ -950,7 +957,6 @@ 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)
@@ -977,7 +983,7 @@ 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)
@@ -1069,12 +1075,14 @@ 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);
}

@@ -1464,6 +1472,7 @@ static int garmin_attach(struct usb_seri
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);
@@ -1479,6 +1488,7 @@ static void garmin_disconnect(struct usb

dbg("%s", __func__);

+ usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
usb_kill_urb(port->interrupt_in_urb);
del_timer_sync(&garmin_data_p->timer);
}