svn commit: r307056 - stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Alexander Motin]

Author: mav
Date: Tue Oct 11 16:50:45 2016
New Revision: 307056
URL: https://svnweb.freebsd.org/changeset/base/307056

Log:
  MFC r305199: MFV r302648: 7019 zfsdev_ioctl skips secpolicy when FKIOCTL is set
  
  Note that the bulk of the upstream change is not applicable to FreeBSD
  and the affected files are not even in the vendor area.
  
  illumos/illumos-gate at 45b1747515a17db45e8971501ee84a26bdff37b2
  https://github.com/illumos/illumos-gate/commit/45b1747515a17db45e8971501ee84a26bdff37b2
  
  https://www.illumos.org/issues/7019
    Currently zfsdev_ioctl, when confronted by a request with the FKIOCTL flag set,
    skips all processing of secpolicy functions. This means that ZFS is not doing
    any kind of verification of the credentials or access rights of the caller and
    assuming that (as it is an in-kernel client) all such checks have already been
    done.
    This turns out to be quite a dangerous assumption, especially with respect to
    sdev. In general I don't think it's particularly reasonable to offload this
    enforcement of access rights onto other kernel subsystems when ZFS has some
    particular local semantics in this area (delegated datasets etc) and does not
    provide any kind of API to allow other subsystems to avoid code duplication
    when doing it. ZFS should apply its normal access policy to requests from
    within the kernel, and callers should take care to give it the correct
    credentials and call it from the correct context in order to get the results
    they need.
    You can observe the currently unfortunate consequences of this bug in any non-
    global zone that has access to /dev/zvol or any subset of it via sdev profiles.
    In particular, a zone used to contain a KVM or similar which has a single zvol
    passed through to it using a <device match= block in its zone XML.
    Even though sdev makes something of an attempt to control for whether the
    caller should have access to nodes in /dev/zvol, it doesn't do this correctly,
    or really at all in the lookup call path. So, if we have a zone that's been
    given access to any part of /dev/zvol, it can simply look up the full path to
    any other zvol on the entire system, and the node will appear and be able to be
    used.
  
  Reviewed by: Robert Mustacchi <rm at joyent.com>
  Reviewed by: Richard Lowe <richlowe at richlowe.net>
  Reviewed by: Matthew Ahrens <mahrens at delphix.com>
  Approved by: Dan McDonald <danmcd at omniti.com>
  Author: Alex Wilson <alex.wilson at joyent.com>

Modified:
  stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
==============================================================================
--- stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c	Tue Oct 11 16:49:16 2016	(r307055)
+++ stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c	Tue Oct 11 16:50:45 2016	(r307056)
@@ -26,7 +26,7 @@
  * Copyright 2014 Xin Li <delphij at FreeBSD.org>. All rights reserved.
  * Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved.
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- * Copyright (c) 2014, Joyent, Inc. All rights reserved.
+ * Copyright (c) 2014, 2016 Joyent, Inc. All rights reserved.
  * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
@@ -6366,7 +6366,7 @@ zfsdev_ioctl(struct cdev *dev, u_long zc
 		break;
 	}
 
-	if (error == 0 && !(flag & FKIOCTL))
+	if (error == 0)
 		error = vec->zvec_secpolicy(zc, innvl, cr);
 
 	if (error != 0)