Bug 1491224 (CVE-2017-12154)

Summary:	CVE-2017-12154 Kernel: kvm: nVMX: L2 guest could access hardware(L0) CR8 register
Product:	[Other] Security Response	Reporter:	Prasad Pandit <ppandit>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	airlied, ajax, aquini, bhu, blc, bskeggs, dhoward, eparis, esandeen, fhrbata, hdegoede, hkrzesin, hwkernel-mgr, iboverma, ichavero, itamar, jarodwilson, jforbes, jglisse, jkacur, jonathan, josef, jross, jwboyer, kernel-maint, kernel-mgr, knoel, labbott, lgoncalv, linville, matt, mchehab, mcressma, mjg59, mlangsdo, mmilgram, nhorman, nmurray, plougher, quintela, rt-maint, rvrbovsk, sheldon.corey, sheldon.corey, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	Linux kernel built with the KVM visualization support (CONFIG_KVM), with nested visualization (nVMX) feature enabled (nested=1), is vulnerable to a crash due to disabled external interrupts. As L2 guest could access (r/w) hardware CR8 register of the host(L0). In a nested visualization setup, L2 guest user could use this flaw to potentially crash the host(L0) resulting in DoS.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 03:25:09 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1491225, 1491231, 1491232, 1491233, 1695839
Bug Blocks:	1488027

Description Prasad Pandit 2017-09-13 11:11:28 UTC

Linux kernel built with the KVM virtualisation support(CONFIG_KVM),
with nested virtualisation(nVMX) feature enabled(nested=1), is vulnerable
to a crash due to disabled external interrupts. As L2 guest could access(r/w)
hardware CR8 register of the host(L0).

In a nested virtualisation setup, L2 guest user could use this flaw
to potentially crash the host(L0) resulting in DoS.

Upstream patch
--------------
   -> https://git.kernel.org/linus/51aa68e7d57e3217192d88ce90fd5b8ef29ec94f

Reference:
----------
   -> http://www.openwall.com/lists/oss-security/2017/09/26/3

Comment 1 Prasad Pandit 2017-09-13 11:12:54 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1491225]

Comment 2 Prasad Pandit 2017-09-13 11:24:55 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1491231]

Comment 4 Prasad Pandit 2017-09-13 11:49:31 UTC

Statement:

This issue does not affect the versions of the kernel package as shipped with
Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2.

Comment 5 Prasad Pandit 2017-09-13 19:09:29 UTC

Acknowledgments:

Name: Jim Mattson (Google.com)

Comment 7 Justin M. Forbes 2018-01-29 16:34:34 UTC

This was fixed for Fedora with the 4.13.5 stable updates

Comment 8 errata-xmlrpc 2018-04-10 08:07:04 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2018:0676 https://access.redhat.com/errata/RHSA-2018:0676

Comment 9 errata-xmlrpc 2018-04-10 09:30:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2018:1062 https://access.redhat.com/errata/RHSA-2018:1062

Comment 13 errata-xmlrpc 2019-07-30 09:08:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.4 Extended Update Support

Via RHSA-2019:1946 https://access.redhat.com/errata/RHSA-2019:1946