usb: misc: lvs: fix race condition in disconnect handling

[ Upstream commit c4ba329cabca7c839ab48fb58b5bcc2582951a48 ]

There is a small window during which the an URB may
remain active after disconnect has returned. If in that case
already freed memory may be accessed and executed.

The fix is to poison the URB befotre the work is flushed.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Oliver Neukum 2017-03-14 12:05:07 +01:00 committed by Greg Kroah-Hartman
parent 84b63638ca
commit e6e868c750

View File

@ -433,6 +433,7 @@ static void lvs_rh_disconnect(struct usb_interface *intf)
struct lvs_rh *lvs = usb_get_intfdata(intf);
sysfs_remove_group(&intf->dev.kobj, &lvs_attr_group);
usb_poison_urb(lvs->urb); /* used in scheduled work */
flush_work(&lvs->rh_work);
usb_free_urb(lvs->urb);
}