OracleVM 3.2 : xen (OVMSA-2017-0149)

High Nessus Plugin ID 102907

Synopsis

The remote OracleVM host is missing one or more security updates.

Description

The remote OracleVM system is missing necessary patches to address critical security updates :

- From e26560a4b056dad6d85ffd9ebfad9565f210a9cc Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 30 May 2012 09:22:17 +0100 Subject: [PATCH] gnttab: don't use domain lock for serialization Instead use the affected domain's grant table lock, at once reducing the scopes during which locks are being held and hence allowing significantly better parallelism.

Committed-by: Keir Fraser Conflict:
xen/common/grant_table.c xen/arch/x86/mm.c

- From: Jan Beulich Subject: gnttab: correct pin status fixup for copy Regardless of copy operations only setting GNTPIN_hst*, GNTPIN_dev* also need to be taken into account when deciding whether to clear
_GTF_[read,writ]ing. At least for consistency with code elsewhere the read part better doesn't use any mask at all. This is XSA-230. (CVE-2017-12855)

- From 3aab881c7331cf93ffd8d2f2dd9adfd18ed4fc99 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Tue, 20 Jun 2017 19:18:54 +0100 Subject: [PATCH] x86/grant: Disallow misaligned PTEs Pagetable entries must be aligned to function correctly. Disallow attempts from the guest to have a grant PTE created at a misaligned address, which would result in corruption of the L1 table with largely-guest-controlled values. This is XSA-227 (CVE-2017-12137)

- Prerequisite patch for xsa227-4.5.patch There is no macro ASSERT_UNREACHABLE before OVM3.4 which is needed by xsa227-4.5.patch This chunk is picked from upstream commit cacdb0faaa121ac8f792d5bd34cc6bc7c72d21da (CVE-2017-12137)

- From: Andrew Cooper Subject: grant_table: Default to v1, and disallow transitive grants The reference counting and locking discipline for transitive grants is broken.
Their use is therefore declared out of security support.
This is XSA-226. Transitive grants are expected to be unconditionally available with grant table v2. Hiding transitive grants alone is an ABI breakage for the guest. Modern versions of Linux and the Windows PV drivers use grant table v1, but older versions did use v2. In principle, disabling gnttab v2 entirely is the safer way to cause guests to avoid using transitive grants. However, some older guests which defaulted to using gnttab v2 don't tolerate falling back from v2 to v1 over migrate. This patch introduces a new command line option to control grant table behaviour. One suboption allows a choice of the maximum grant table version Xen will allow the guest to use, and defaults to v2. A different suboption independently controls whether transitive grants can be used. The default case is:
gnttab=max_ver:2 To disable gnttab v2 entirely, use:
gnttab=max_ver:1 To allow gnttab v2 and transitive grants, use: gnttab=max_ver:2,transitive

Ignore the chunk for docs/misc/xen-command-line.markdown as no such file for OVM3.2 (CVE-2017-12135)

- From 8aed1f12c4c087c5b31cbee8636b3d2d25efb363 Mon Sep 17 00:00:00 2001 From: Andres Lagar-Cavilla Date: Wed, 22 Aug 2012 22:27:50 +0100 Subject: [PATCH] Fix shared entry status for grant copy operation on paged-out g fn The unwind path was not clearing the shared entry status bits. This was BSOD-ing guests on network activity under certain configurations. Also: * sed the fixup method name to signal it's related to grant copy. * use atomic clear flag ops during fixup.

Committed-by: Keir Fraser Conflict:
xen/common/grant_table.c Prerequisite patch for XSA-226 fix (CVE-2017-12135)

- From 69549b08eb9bd3a525c07a97d952673a3d02c76a Mon Sep 17 00:00:00 2001 From: Annie Li Date: Fri, 7 Jul 2017 14:36:08 -0400 Subject: [PATCH] xen: increase default max grant frames and max maptrack frames Commit 9dfba034e increase default max grant frames to 128 which is still not enough when the guest has more cpus and vbd/vif devices, so set it to 256. Also the default max maptrack frames needs to be increased accordingly.

Solution

Update the affected xen / xen-devel / xen-tools packages.

See Also

http://www.nessus.org/u?3f5b6d94

Plugin Details

Severity: High

ID: 102907

File Name: oraclevm_OVMSA-2017-0149.nasl

Version: 3.4

Type: local

Published: 2017/09/01

Modified: 2018/07/25

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 7.2

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:oracle:vm:xen, p-cpe:/a:oracle:vm:xen-devel, p-cpe:/a:oracle:vm:xen-tools, cpe:/o:oracle:vm_server:3.2

Required KB Items: Host/local_checks_enabled, Host/OracleVM/release, Host/OracleVM/rpm-list

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2017/08/31

Reference Information

CVE: CVE-2017-12135, CVE-2017-12137, CVE-2017-12855