Bug 1329653 (CVE-2016-3699)

Summary:	CVE-2016-3699 kernel: ACPI table override allowed when securelevel is enabled
Product:	[Other] Security Response	Reporter:	Vladis Dronov <vdronov>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	aquini, bhu, dhoward, fhrbata, iboverma, jkacur, jross, kernel-mgr, kstutsma, lgoncalv, matt, mcressma, nmurray, plougher, rvrbovsk, security-response-team, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 02:50:57 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:	1316304, 1329683, 1329684
Bug Blocks:	1316516

Description Vladis Dronov 2016-04-22 13:29:12 UTC

A vulnerability was found in the RHEL7.2 kernel. When RHEL 7.2 is booted with UEFI Secure Boot enabled, securelevel is set. The kernel uses the state of securelevel to prevent userspace from inserting untrusted privileged code at runtime.

The ACPI tables provided by firmware can be overwritten using the initrd. From the kernel documentation:

  If the ACPI_INITRD_TABLE_OVERRIDE compile option is true, it is possible to
  override nearly any ACPI table provided by the BIOS with an instrumented,
  modified one.

RHEL 7.2 has CONFIG_ACPI_INITRD_TABLE_OVERRIDE kernel config option enabled, and will load ACPI tables appended to the initrd, even if booted with UEFI Secure Boot enabled and securelevel set.

Upstream patch:

https://github.com/mjg59/linux/commit/a4a5ed2835e8ea042868b7401dced3f517cafa76

Comment 1 Vladis Dronov 2016-04-22 13:29:25 UTC

Acknowledgments:

Name: Linn Crosetto (HP)

Comment 2 Adam Mariš 2016-04-22 14:24:33 UTC

Internal CVE assignment: CVE-2016-3699

Comment 5 Vladis Dronov 2016-04-22 14:57:17 UTC

Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5 and 6 as the code with the flaw is not present in the products listed.

This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 7 and MRG-2. Future Linux kernel updates for the respective releases might address this issue.

Comment 7 errata-xmlrpc 2016-11-03 16:04:35 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2574 https://rhn.redhat.com/errata/RHSA-2016-2574.html

Comment 8 errata-xmlrpc 2016-11-03 19:48:13 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2584 https://rhn.redhat.com/errata/RHSA-2016-2584.html

Comment 9 errata-xmlrpc 2016-11-03 21:33:56 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2574 https://rhn.redhat.com/errata/RHSA-2016-2574.html

Comment 10 errata-xmlrpc 2016-11-03 21:49:20 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2584 https://rhn.redhat.com/errata/RHSA-2016-2584.html