Bug 1329653 (CVE-2016-3699) - CVE-2016-3699 kernel: ACPI table override allowed when securelevel is enabled
Summary: CVE-2016-3699 kernel: ACPI table override allowed when securelevel is enabled
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2016-3699
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1316304 1329683 1329684
Blocks: 1316516
TreeView+ depends on / blocked
 
Reported: 2016-04-22 13:29 UTC by Vladis Dronov
Modified: 2021-02-17 04:00 UTC (History)
17 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2019-06-08 02:50:57 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2016:2574 0 normal SHIPPED_LIVE Important: kernel security, bug fix, and enhancement update 2016-11-03 12:06:10 UTC
Red Hat Product Errata RHSA-2016:2584 0 normal SHIPPED_LIVE Important: kernel-rt security, bug fix, and enhancement update 2016-11-03 12:08:49 UTC

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
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