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@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@joyent.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Alex Wilson <alex.wilson@joyent.com>

0 files changed, 0 insertions, 0 deletions