Bug 1191363 - (CVE-2021-28702) VUL-0: CVE-2021-28702: xen: PCI devices with RMRRs not deassigned correctly (XSA-386)
(CVE-2021-28702)
VUL-0: CVE-2021-28702: xen: PCI devices with RMRRs not deassigned correctly (...
Status: RESOLVED FIXED
Classification: Novell Products
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents
unspecified
Other Other
: P3 - Medium : Normal
: ---
Assigned To: Security Team bot
Security Team bot
https://smash.suse.de/issue/311787/
CVSSv3.1:SUSE:CVE-2021-28702:6.8:(AV:...
:
Depends on:
Blocks:
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Reported: 2021-10-06 07:38 UTC by Alexander Bergmann
Modified: 2022-01-27 15:59 UTC (History)
5 users (show)

See Also:
Found By: ---
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
IT Deployment: ---


Attachments
xsa386.patch (1.16 KB, patch)
2021-10-06 07:38 UTC, Alexander Bergmann
Details | Diff

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Description Alexander Bergmann 2021-10-06 07:38:20 UTC
Xen Security Advisory CVE-2021-28702 / XSA-386

            PCI devices with RMRRs not deassigned correctly

ISSUE DESCRIPTION
=================

Certain PCI devices in a system might be assigned Reserved Memory
Regions (specified via Reserved Memory Region Reporting, "RMRR").
These are typically used for platform tasks such as legacy USB
emulation.

If such a device is passed through to a guest, then on guest shutdown
the device is not properly deassigned.  The IOMMU configuration for
these devices which are not properly deassigned ends up pointing to a
freed data structure, including the IO Pagetables.

Subsequent DMA or interrupts from the device will have unpredictable
behaviour, ranging from IOMMU faults to memory corruption.

IMPACT
======

Administrators of guests which have been assigned RMRR-using PCI
devices can cause denial of service and other problems, possibly
including escalation of privilege.

VULNERABLE SYSTEMS
==================

All versions of Xen from at least 4.4 onwards are vulnerable.

Only Intel x86 systems are affected.  AMD x86 systems, and Arm
systems, are all unaffected.

Only systems using PCI passthrough are affected.  (And then, only if
the assigned devices have RMRRs, but whether a device advertises RMRRs
is not easy to discern.)

MITIGATION
==========

There is no mitigation (other than not passing through PCI devices
with RMRRs to guests).

RESOLUTION
==========

Applying the appropriate attached patch resolves this issue.

Note that patches for released versions are generally prepared to
apply to the stable branches, and may not apply cleanly to the most
recent release tarball.  Downstreams are encouraged to update to the
tip of the stable branch before applying these patches.

xsa386.patch           xen-unstable - Xen 4.12.x

$ sha256sum xsa386*
f2f83c825e249bba9454437b48bbd8307fe7a224f56484388a67af124dfd279b  xsa386.patch
$

NOTE CONCERNING LACK OF EMBARGO
===============================

This issue was reported and debugged in public before the security nature
became apparent.

References:
https://xenbits.xen.org/xsa/advisory-386.html
Comment 1 Alexander Bergmann 2021-10-06 07:38:46 UTC
Created attachment 852961 [details]
xsa386.patch
Comment 2 Gianluca Gabrielli 2021-11-02 14:29:01 UTC
            Xen Security Advisory CVE-2021-28702 / XSA-386
                               version 2

            PCI devices with RMRRs not deassigned correctly

UPDATES IN VERSION 2
====================

Updated/corrected information about vulnerable versions.
Upstream Xen 4.12 is not affected.

There is no harm from applying the patch to an unaffected version.
Comment 4 Swamp Workflow Management 2021-12-01 21:01:25 UTC
SUSE-SU-2021:3852-1: An update that fixes 7 vulnerabilities is now available.

Category: security (moderate)
Bug References: 1027519,1191363,1191510,1192554,1192557,1192559
CVE References: CVE-2021-28702,CVE-2021-28704,CVE-2021-28705,CVE-2021-28706,CVE-2021-28707,CVE-2021-28708,CVE-2021-28709
JIRA References: 
Sources used:
SUSE Linux Enterprise Software Development Kit 12-SP5 (src):    xen-4.12.4_16-3.55.1
SUSE Linux Enterprise Server 12-SP5 (src):    xen-4.12.4_16-3.55.1

NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
Comment 5 Swamp Workflow Management 2021-12-03 14:50:39 UTC
SUSE-SU-2021:3888-1: An update that fixes 7 vulnerabilities is now available.

Category: security (moderate)
Bug References: 1027519,1191363,1192554,1192557,1192559
CVE References: CVE-2021-28702,CVE-2021-28704,CVE-2021-28705,CVE-2021-28706,CVE-2021-28707,CVE-2021-28708,CVE-2021-28709
JIRA References: 
Sources used:
SUSE MicroOS 5.0 (src):    xen-4.13.4_02-3.40.1
SUSE Linux Enterprise Module for Server Applications 15-SP2 (src):    xen-4.13.4_02-3.40.1
SUSE Linux Enterprise Module for Basesystem 15-SP2 (src):    xen-4.13.4_02-3.40.1

NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
Comment 6 Swamp Workflow Management 2021-12-06 18:36:10 UTC
openSUSE-SU-2021:1543-1: An update that fixes 7 vulnerabilities is now available.

Category: security (moderate)
Bug References: 1027519,1191363,1192554,1192557,1192559
CVE References: CVE-2021-28702,CVE-2021-28704,CVE-2021-28705,CVE-2021-28706,CVE-2021-28707,CVE-2021-28708,CVE-2021-28709
JIRA References: 
Sources used:
openSUSE Leap 15.2 (src):    xen-4.13.4_02-lp152.2.33.1
Comment 7 Swamp Workflow Management 2021-12-07 20:17:41 UTC
SUSE-SU-2021:3968-1: An update that fixes 7 vulnerabilities is now available.

Category: security (moderate)
Bug References: 1027519,1191363,1192554,1192557,1192559
CVE References: CVE-2021-28702,CVE-2021-28704,CVE-2021-28705,CVE-2021-28706,CVE-2021-28707,CVE-2021-28708,CVE-2021-28709
JIRA References: 
Sources used:
SUSE MicroOS 5.1 (src):    xen-4.14.3_04-3.15.1
SUSE Linux Enterprise Module for Server Applications 15-SP3 (src):    xen-4.14.3_04-3.15.1
SUSE Linux Enterprise Module for Basesystem 15-SP3 (src):    xen-4.14.3_04-3.15.1

NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
Comment 8 Swamp Workflow Management 2021-12-07 20:29:26 UTC
openSUSE-SU-2021:3968-1: An update that fixes 7 vulnerabilities is now available.

Category: security (moderate)
Bug References: 1027519,1191363,1192554,1192557,1192559
CVE References: CVE-2021-28702,CVE-2021-28704,CVE-2021-28705,CVE-2021-28706,CVE-2021-28707,CVE-2021-28708,CVE-2021-28709
JIRA References: 
Sources used:
openSUSE Leap 15.3 (src):    xen-4.14.3_04-3.15.1
Comment 9 Swamp Workflow Management 2021-12-09 14:22:27 UTC
SUSE-SU-2021:3977-1: An update that fixes 8 vulnerabilities is now available.

Category: security (moderate)
Bug References: 1027519,1189632,1191363,1192554,1192557,1192559
CVE References: CVE-2021-28701,CVE-2021-28702,CVE-2021-28704,CVE-2021-28705,CVE-2021-28706,CVE-2021-28707,CVE-2021-28708,CVE-2021-28709
JIRA References: 
Sources used:
SUSE Linux Enterprise Server for SAP 15-SP1 (src):    xen-4.12.4_16-3.57.1
SUSE Linux Enterprise Server 15-SP1-LTSS (src):    xen-4.12.4_16-3.57.1
SUSE Linux Enterprise Server 15-SP1-BCL (src):    xen-4.12.4_16-3.57.1
SUSE Linux Enterprise High Performance Computing 15-SP1-LTSS (src):    xen-4.12.4_16-3.57.1
SUSE Linux Enterprise High Performance Computing 15-SP1-ESPOS (src):    xen-4.12.4_16-3.57.1
SUSE Enterprise Storage 6 (src):    xen-4.12.4_16-3.57.1
SUSE CaaS Platform 4.0 (src):    xen-4.12.4_16-3.57.1

NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
Comment 10 Robert Frohl 2022-01-12 11:04:37 UTC
these codestreams seem to be missing the fix:

- SUSE:SLE-11-SP4:Update/xen
- SUSE:SLE-12-SP2:Update/xen
- SUSE:SLE-12-SP3:Update/xen
- SUSE:SLE-12-SP4:Update/xen
- SUSE:SLE-15:Update/xen
Comment 11 Charles Arnold 2022-01-27 15:41:38 UTC
(In reply to Robert Frohl from comment #10)
> these codestreams seem to be missing the fix:
> 
> - SUSE:SLE-11-SP4:Update/xen
> - SUSE:SLE-12-SP2:Update/xen
> - SUSE:SLE-12-SP3:Update/xen
> - SUSE:SLE-12-SP4:Update/xen
> - SUSE:SLE-15:Update/xen

Only versions 4.12 through 4.15 are affected (we don't ship 4.15).
SLE12-SP5
SLE15-SP1/SP2/SP3

This was changed after the original advisory which stated 4.4 and newer.

https://xenbits.xen.org/xsa/advisory-386.html
Comment 12 Robert Frohl 2022-01-27 15:59:37 UTC
(In reply to Charles Arnold from comment #11)
> (In reply to Robert Frohl from comment #10)
> > these codestreams seem to be missing the fix:
> > 
> > - SUSE:SLE-11-SP4:Update/xen
> > - SUSE:SLE-12-SP2:Update/xen
> > - SUSE:SLE-12-SP3:Update/xen
> > - SUSE:SLE-12-SP4:Update/xen
> > - SUSE:SLE-15:Update/xen
> 
> Only versions 4.12 through 4.15 are affected (we don't ship 4.15).
> SLE12-SP5
> SLE15-SP1/SP2/SP3
> 
> This was changed after the original advisory which stated 4.4 and newer.
> 
> https://xenbits.xen.org/xsa/advisory-386.html

thanks Charles, updated CVE pages data accordingly. Done.