Bug 1792167 (CVE-2019-3016)

Summary:	CVE-2019-3016 kernel: kvm: Information leak within a KVM guest
Product:	[Other] Security Response	Reporter:	msiddiqu
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	acaringi, airlied, bdas, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, jmaloy, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, pbonzini, ppandit, qzhao, rt-maint, rvrbovsk, security-response-team, steved, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A flaw was found in the way Linux kernel's KVM hypervisor handled deferred TLB flush requests from guest. A race condition may occur between the guest issuing a deferred TLB flush request to KVM, and then KVM handling and acknowledging it. This may result in invalid address translations from TLB being used to access guest memory, leading to a potential information leakage issue. An attacker may use this flaw to access guest memory locations that it should not have access to.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-07-21 13:27:47 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:	1795128, 1795129, 1796650, 1857755, 1857756
Bug Blocks:	1792163

Description msiddiqu 2020-01-17 08:11:17 UTC

A flaw was found in the way Linux kernel's KVM hypervisor handled deferred TLB
flush requests from guest. A race condition may occur between guest issuing
a deferred TLB flush request to KVM and KVM handling and acknowledging it.
This may result in invalid address translations from TLB being used to access
guest memory, leading to potential information leakage issue.

A guest user/process may use this flaw to access guest memory locations which
it should not have access to.

Upstream patches:
-----------------
  -> https://git.kernel.org/linus/a6bd811f1209fe1c64c9f6fd578101d6436c6b6e
  -> https://git.kernel.org/linus/b043138246a41064527cf019a3d51d9f015e9796
  -> https://git.kernel.org/linus/917248144db5d7320655dbb41d3af0b8a0f3d589
  -> https://git.kernel.org/linus/1eff70a9abd46f175defafd29bc17ad456f398a7
  -> https://git.kernel.org/linus/8c6de56a42e0c657955e12b882a81ef07d1d073e
  -> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=CVE-2019-3016

Comment 4 Petr Matousek 2020-01-30 13:55:07 UTC

Mitigation:

This issue can only be resolved by applying updates.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Comment 5 Petr Matousek 2020-01-30 20:35:53 UTC

External References:

https://www.openwall.com/lists/oss-security/2020/01/30/4

Comment 6 Petr Matousek 2020-01-30 20:37:20 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1796650]

Comment 8 Justin M. Forbes 2020-03-20 15:38:55 UTC

This issue was fixed for Fedora with the 5.4.19 stable kernel updates.

Comment 10 errata-xmlrpc 2020-07-21 11:04:45 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:3010 https://access.redhat.com/errata/RHSA-2020:3010

Comment 11 errata-xmlrpc 2020-07-21 11:23:03 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:3016 https://access.redhat.com/errata/RHSA-2020:3016

Comment 12 Product Security DevOps Team 2020-07-21 13:27:47 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2019-3016