Bug 1965461 (CVE-2021-22543)

Summary:	CVE-2021-22543 kernel: Improper handling of VM_IO\|VM_PFNMAP vmas in KVM can bypass RO checks
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, asavkov, bhu, blc, bmasney, brdeoliv, bskeggs, chwhite, crwood, dblechte, dfediuck, dhoward, dvlasenk, eedri, fhrbata, fpacheco, hdegoede, hkrzesin, jarodwilson, jeremy, jforbes, jglisse, jlelli, joe.lawrence, jonathan, josef, jpoimboe, jshortt, jstancek, jthierry, jwboyer, kcarcia, kernel-maint, kernel-mgr, kpatch-maint, lgoncalv, linville, masami256, mchehab, mgoldboi, michal.skrivanek, mlangsdo, mvanderw, nmurray, nobody, ptalbert, qzhao, rhandlin, rvrbovsk, sbonazzo, sherold, steved, walters, wcosta, williams, ycote, yturgema, zhilli
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.13	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the Linux kernel’s KVM implementation, where improper handing of the VM_IO\|VM_PFNMAP VMAs in KVM bypasses RO checks and leads to pages being freed while still accessible by the VMM and guest. This flaw allows users who can start and control a VM to read/write random pages of memory, resulting in local privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, and system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-08-10 13:28:48 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:	1973088, 1965462, 1973042, 1973043, 1973044, 1973049, 1973050, 1973051, 1973089, 1973090, 1973091, 1975511, 1975512, 1975513, 1975514, 1975515, 1975516, 1975517, 1975748, 1975750, 1975751, 1975752, 1975753, 1975754, 1975755, 1975756, 1975757, 1975758, 1975759, 1975760, 1975761, 1975762, 1975764, 1975765, 1975766, 1975793, 1975794, 1994422
Bug Blocks:	1965463

Description Pedro Sampaio 2021-05-27 18:19:53 UTC

An issue was discovered in the Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation.

References:

https://github.com/google/security-research/security/advisories/GHSA-7wq5-phmq-m584
http://www.openwall.com/lists/oss-security/2021/05/26/3
http://www.openwall.com/lists/oss-security/2021/05/26/4
http://www.openwall.com/lists/oss-security/2021/05/26/5

Comment 1 Pedro Sampaio 2021-05-27 18:20:44 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1965462]

Comment 9 Mauro Matteo Cascella 2021-06-22 10:43:57 UTC

Upstream fix aiming to address the first PoC from google advisory (vvar_write.c):
https://github.com/torvalds/linux/commit/bd2fae8d
https://github.com/torvalds/linux/commit/a9545779

Note that the second PoC (kernel_write.c) is still being worked on, see https://seclists.org/oss-sec/2021/q2/169.

Comment 21 Mauro Matteo Cascella 2021-06-28 07:54:49 UTC

Upstream fix:
https://github.com/torvalds/linux/commit/f8be156be163a052a067306417cd0ff679068c97

Comment 22 errata-xmlrpc 2021-08-10 11:13:14 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:3044 https://access.redhat.com/errata/RHSA-2021:3044

Comment 23 errata-xmlrpc 2021-08-10 13:08:04 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:3088 https://access.redhat.com/errata/RHSA-2021:3088

Comment 24 errata-xmlrpc 2021-08-10 13:14:35 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:3057 https://access.redhat.com/errata/RHSA-2021:3057

Comment 25 Product Security DevOps Team 2021-08-10 13:28:48 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-2021-22543

Comment 26 errata-xmlrpc 2021-08-17 08:29:16 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Extended Update Support

Via RHSA-2021:3173 https://access.redhat.com/errata/RHSA-2021:3173

Comment 27 errata-xmlrpc 2021-08-17 08:31:24 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Extended Update Support

Via RHSA-2021:3181 https://access.redhat.com/errata/RHSA-2021:3181

Comment 29 errata-xmlrpc 2021-08-19 15:48:38 UTC

This issue has been addressed in the following products:

  Red Hat Virtualization 4 for Red Hat Enterprise Linux 8

Via RHSA-2021:3235 https://access.redhat.com/errata/RHSA-2021:3235

Comment 30 errata-xmlrpc 2021-08-31 08:53:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2021:3375 https://access.redhat.com/errata/RHSA-2021:3375

Comment 31 errata-xmlrpc 2021-08-31 09:04:05 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2021:3380 https://access.redhat.com/errata/RHSA-2021:3380

Comment 32 errata-xmlrpc 2021-08-31 09:20:46 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2021:3363 https://access.redhat.com/errata/RHSA-2021:3363

Comment 33 errata-xmlrpc 2021-10-05 07:52:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.4 Advanced Update Support

Via RHSA-2021:3725 https://access.redhat.com/errata/RHSA-2021:3725

Comment 34 errata-xmlrpc 2021-10-12 07:24:27 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.2 Advanced Update Support

Via RHSA-2021:81932 https://access.redhat.com/errata/RHSA-2021:81932

Comment 35 errata-xmlrpc 2021-10-12 07:44:10 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.3 Advanced Update Support

Via RHSA-2021:3766 https://access.redhat.com/errata/RHSA-2021:3766

Comment 36 errata-xmlrpc 2021-10-12 09:34:28 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2021:3768 https://access.redhat.com/errata/RHSA-2021:3768

Comment 37 errata-xmlrpc 2021-10-12 15:04:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Advanced Update Support
  Red Hat Enterprise Linux 7.6 Update Services for SAP Solutions
  Red Hat Enterprise Linux 7.6 Telco Extended Update Support

Via RHSA-2021:3812 https://access.redhat.com/errata/RHSA-2021:3812

Comment 38 errata-xmlrpc 2021-10-12 15:05:12 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Update Services for SAP Solutions

Via RHSA-2021:3814 https://access.redhat.com/errata/RHSA-2021:3814

Comment 39 errata-xmlrpc 2021-10-12 15:29:01 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2021:3801 https://access.redhat.com/errata/RHSA-2021:3801

Comment 40 errata-xmlrpc 2021-10-12 15:29:19 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2021:3802 https://access.redhat.com/errata/RHSA-2021:3802

Comment 42 errata-xmlrpc 2021-10-20 09:52:41 UTC

This issue has been addressed in the following products:

  Red Hat Virtualization 4 for Red Hat Enterprise Linux 7

Via RHSA-2021:3943 https://access.redhat.com/errata/RHSA-2021:3943

Comment 43 errata-xmlrpc 2021-10-26 07:38:00 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Advanced Update Support
  Red Hat Enterprise Linux 7.7 Update Services for SAP Solutions
  Red Hat Enterprise Linux 7.7 Telco Extended Update Support

Via RHSA-2021:3987 https://access.redhat.com/errata/RHSA-2021:3987

Comment 44 errata-xmlrpc 2021-10-26 16:20:59 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Update Services for SAP Solutions

Via RHSA-2021:4000 https://access.redhat.com/errata/RHSA-2021:4000

Comment 45 errata-xmlrpc 2022-07-19 16:23:23 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6 Extended Lifecycle Support

Via RHSA-2022:5640 https://access.redhat.com/errata/RHSA-2022:5640