| Summary: | <app-emulation/xen-{4.2.4-r1,4.3.2-r1,4.4.0-r1}: Guest triggerable AMD CPU erratum may cause host hang (CVE-2013-6885) (XSA-82) | ||
|---|---|---|---|
| Product: | Gentoo Security | Reporter: | Agostino Sarubbo <ago> |
| Component: | Vulnerabilities | Assignee: | Gentoo Security <security> |
| Status: | RESOLVED FIXED | ||
| Severity: | minor | CC: | idella4, xen |
| Priority: | Normal | ||
| Version: | unspecified | ||
| Hardware: | All | ||
| OS: | Linux | ||
| URL: | http://www.openwall.com/lists/oss-security/2014/02/19/6 | ||
| Whiteboard: | B3 [glsa] | ||
| Package list: | Runtime testing required: | --- | |
Is this fixed in release big bug fix Bug 500530? yes, this bug is already fixed, first addressed in bug 500530 (for 4.2.3), later also included in bug #505714 (for version 4.2.4) Arches and Mainter(s), Thank you for your work. Added to an existing GLSA request. This issue was resolved and addressed in GLSA 201407-03 at http://security.gentoo.org/glsa/glsa-201407-03.xml by GLSA coordinator Mikle Kolyada (Zlogene). |
From ${URL} : Xen Security Advisory CVE-2013-6885 / XSA-82 version 4 Guest triggerable AMD CPU erratum may cause host hang UPDATES IN VERSION 4 ==================== The original fix for 4.2.x and 4.1.x was found to deal with 64-bit hypervisors only. Incremental patches to also address 32-bit ones are now being provided in addition. ISSUE DESCRIPTION ================= AMD CPU erratum 793 "Specific Combination of Writes to Write Combined Memory Types and Locked Instructions May Cause Core Hang" describes a situation under which a CPU core may hang. IMPACT ====== A malicious guest administrator can mount a denial of service attack affecting the whole system. VULNERABLE SYSTEMS ================== The vulnerability is applicable only to family 16h model 00h-0fh AMD CPUs. Such CPUs running Xen versions 3.3 onwards are vulnerable. We have not checked earlier versions of Xen. HVM guests can always exploit the vulnerability if it is present. PV guests can exploit the vulnerability only if they have been granted access to physical device(s). Non-AMD CPUs are not vulnerable. CREDITS ======= This issue's security impact was discovered by Jan Beulich. MITIGATION ========== This issue can be avoided by neither running HVM guests, nor assigning PCI devices to PV guests. RESOLUTION ========== The attached xsa82.patch contains a software workaround which resolves this issue for 64-bit hypervisors. To also resolve the issue on 32-bit hypervisors (Xen 4.2.x and 4.1.x only), the respective attached xsa82-4.?-32bit.patch needs to be applied on top. Alternatively, the recommended workaround can be implemented in firmware, so a suitable firmware update will resolve the issue. If you require a firmware update please consult your vendor. xsa82.patch Xen 4.1.x, Xen 4.2.x, Xen 4.3.x, xen-unstable xsa82-4.1-32bit.patch Xen 4.1.x xsa82-4.2-32bit.patch Xen 4.2.x @maintainer(s): after the bump, in case we need to stabilize the package, please let us know if it is ready for the stabilization or not.