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Re: Xen Security Advisory 378 v3 (CVE-2021-28694,CVE-2021-28695,CVE-2021-28696) - IOMMU page mapping issues on x86
From: Jason Andryuk <jandryuk () gmail com>
Date: Wed, 1 Sep 2021 09:22:14 -0400
On Wed, Sep 1, 2021 at 5:34 AM Xen.org security team <security () xen org> wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Xen Security Advisory CVE-2021-28694,CVE-2021-28695,CVE-2021-28696 / XSA-378 version 3 IOMMU page mapping issues on x86 UPDATES IN VERSION 3 ==================== Warn about dom0=pvh breakage in Resolution section. ISSUE DESCRIPTION ================= Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694).
Hi, Is there a way to identify if a system's ACPI tables have untranslated regions? Does it show up in xen or linux dmesg or can it be identified in sysfs? Thanks, Jason
Current thread:
- Xen Security Advisory 378 v3 (CVE-2021-28694,CVE-2021-28695,CVE-2021-28696) - IOMMU page mapping issues on x86 Xen . org security team (Sep 01)
- Re: Xen Security Advisory 378 v3 (CVE-2021-28694,CVE-2021-28695,CVE-2021-28696) - IOMMU page mapping issues on x86 Jason Andryuk (Sep 01)