linux-kernel - [PATCH v4 0/3] Xen iopl fixes

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Date:	Wed, 16 Mar 2016 14:14:19 -0700
From:	Andy Lutomirski <luto@...nel.org>
To:	x86@...nel.org, Andrew Cooper <andrew.cooper3@...rix.com>,
	Jan Beulich <JBeulich@...e.com>
Cc:	Borislav Petkov <bp@...en8.de>,
	David Vrabel <david.vrabel@...rix.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	linux-kernel@...r.kernel.org, Andy Lutomirski <luto@...nel.org>
Subject: [PATCH v4 0/3] Xen iopl fixes

Hi all-

For those who are seeing this for the first time: any 64-bit Xen PV
domain with IO port access privileges (in practice, this means dom0
AFAIK) and any user programs that use iopl(3) (various old X
drivers, presumably) is probably vulnerable to privilege escalations
by unprivileged programs running in the same PV domain.

There's a long public description of the issue here:

http://xenbits.xen.org/xsa/advisory-171.html

Changes from v3:
 - Add Jan's R-b.
 - No longer embargoed

Changes from v2: Pretend v2 never happened...

Changes from v1: Use xen/hypervisor.h instead of xen-ops.h (Jan)

Andy Lutomirski (3):
  selftests/x86: Add a iopl test
  x86/iopl/64: Properly context-switch IOPL on Xen PV
  x86/iopl: Fix iopl capability check on Xen PV

 arch/x86/include/asm/xen/hypervisor.h |   2 +
 arch/x86/kernel/ioport.c              |  12 ++-
 arch/x86/kernel/process_64.c          |  12 +++
 arch/x86/xen/enlighten.c              |   2 +-
 tools/testing/selftests/x86/Makefile  |   2 +-
 tools/testing/selftests/x86/iopl.c    | 135 ++++++++++++++++++++++++++++++++++
 6 files changed, 160 insertions(+), 5 deletions(-)
 create mode 100644 tools/testing/selftests/x86/iopl.c

-- 
2.5.0