Bugzilla – Bug 1218851
VUL-0: CVE-2023-46839: xen: phantom functions assigned to incorrect contexts (XSA-449)
Last modified: 2024-05-10 17:50:06 UTC
Public via https://xenbits.xen.org/xsa/advisory-449.html Xen Security Advisory CVE-2023-46839 / XSA-449 version 2 pci: phantom functions assigned to incorrect contexts UPDATES IN VERSION 2 ==================== Public release. ISSUE DESCRIPTION ================= PCI devices can make use of a functionality called phantom functions, that when enabled allows the device to generate requests using the IDs of functions that are otherwise unpopulated. This allows a device to extend the number of outstanding requests. Such phantom functions need an IOMMU context setup, but failure to setup the context is not fatal when the device is assigned. Not failing device assignment when such failure happens can lead to the primary device being assigned to a guest, while some of the phantom functions are assigned to a different domain. IMPACT ====== Under certain circumstances a malicious guest assigned a PCI device with phantom functions may be able to access memory from a previous owner of the device. VULNERABLE SYSTEMS ================== Systems running all version of Xen are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only systems using PCI passthrough of devices with phantom functions are affected. MITIGATION ========== There is no mitigation (other than not passing through PCI devices with phantom functions to guests). CREDITS ======= This issue was discovered by Roger Pau Monné of XenServer. 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. xsa449.patch xen-unstable - Xen 4.17.x xsa449-4.16.patch Xen 4.16.x - Xen 4.15.x $ sha256sum xsa449* f77914aae8f917952f66d863d26314875ff96a0d8178f64c94b95825eabbc8a8 xsa449.patch 8f0302c24535ad4c7379469f33afcfdce08ba6db970e0ca1a1bfdd788af6fc6c xsa449-4.16.patch $ DEPLOYMENT DURING EMBARGO ========================= Deployment of the patches described above (or others which are substantially similar) is permitted during the embargo, even on public-facing systems with untrusted guest users and administrators. HOWEVER, deployment of the mitigation is NOT permitted (except where all the affected systems and VMs are administered and used only by organisations which are members of the Xen Project Security Issues Predisclosure List). Specifically, deployment on public cloud systems is NOT permitted. This is because removing/replacing of pass-through devices or their replacement by emulated devices is a guest visible configuration change, which may lead to re-discovery of the issue. Deployment of this mitigation is permitted only AFTER the embargo ends. AND: Distribution of updated software is prohibited (except to other members of the predisclosure list). Predisclosure list members who wish to deploy significantly different patches and/or mitigations, please contact the Xen Project Security Team. (Note: this during-embargo deployment notice is retained in post-embargo publicly released Xen Project advisories, even though it is then no longer applicable. This is to enable the community to have oversight of the Xen Project Security Team's decisionmaking.) For more information about permissible uses of embargoed information, consult the Xen Project community's agreed Security Policy: http://www.xenproject.org/security-policy.html
SUSE-SU-2024:0270-1: An update that solves one vulnerability can now be installed. Category: security (moderate) Bug References: 1218851 CVE References: CVE-2023-46839 Sources used: SUSE Linux Enterprise High Performance Computing 15 SP2 LTSS 15-SP2 (src): xen-4.13.5_10-150200.3.86.1 SUSE Linux Enterprise Server 15 SP2 LTSS 15-SP2 (src): xen-4.13.5_10-150200.3.86.1 SUSE Linux Enterprise Server for SAP Applications 15 SP2 (src): xen-4.13.5_10-150200.3.86.1 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.
SUSE-SU-2024:0269-1: An update that solves one vulnerability can now be installed. Category: security (moderate) Bug References: 1218851 CVE References: CVE-2023-46839 Sources used: SUSE Linux Enterprise High Performance Computing 15 SP1 LTSS 15-SP1 (src): xen-4.12.4_44-150100.3.101.1 SUSE Linux Enterprise Server 15 SP1 LTSS 15-SP1 (src): xen-4.12.4_44-150100.3.101.1 SUSE Linux Enterprise Server for SAP Applications 15 SP1 (src): xen-4.12.4_44-150100.3.101.1 SUSE CaaS Platform 4.0 (src): xen-4.12.4_44-150100.3.101.1 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.
SUSE-SU-2024:0268-1: An update that solves one vulnerability can now be installed. Category: security (moderate) Bug References: 1218851 CVE References: CVE-2023-46839 Sources used: SUSE Linux Enterprise High Performance Computing ESPOS 15 SP4 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise High Performance Computing LTSS 15 SP4 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise Desktop 15 SP4 LTSS 15-SP4 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise Server 15 SP4 LTSS 15-SP4 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise Server for SAP Applications 15 SP4 (src): xen-4.16.5_12-150400.4.46.1 SUSE Manager Proxy 4.3 (src): xen-4.16.5_12-150400.4.46.1 SUSE Manager Retail Branch Server 4.3 (src): xen-4.16.5_12-150400.4.46.1 SUSE Manager Server 4.3 (src): xen-4.16.5_12-150400.4.46.1 openSUSE Leap 15.4 (src): xen-4.16.5_12-150400.4.46.1 openSUSE Leap Micro 5.3 (src): xen-4.16.5_12-150400.4.46.1 openSUSE Leap Micro 5.4 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise Micro for Rancher 5.3 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise Micro 5.3 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise Micro for Rancher 5.4 (src): xen-4.16.5_12-150400.4.46.1 SUSE Linux Enterprise Micro 5.4 (src): xen-4.16.5_12-150400.4.46.1 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.
SUSE-SU-2024:0266-1: An update that solves two vulnerabilities can now be installed. Category: security (moderate) Bug References: 1218851, 1219080 CVE References: CVE-2023-46839, CVE-2023-46840 Sources used: openSUSE Leap 15.5 (src): xen-4.17.3_04-150500.3.21.1 SUSE Linux Enterprise Micro 5.5 (src): xen-4.17.3_04-150500.3.21.1 Basesystem Module 15-SP5 (src): xen-4.17.3_04-150500.3.21.1 Server Applications Module 15-SP5 (src): xen-4.17.3_04-150500.3.21.1 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.
SUSE-SU-2024:0265-1: An update that solves one vulnerability can now be installed. Category: security (moderate) Bug References: 1218851 CVE References: CVE-2023-46839 Sources used: SUSE Linux Enterprise Software Development Kit 12 SP5 (src): xen-4.12.4_44-3.103.1 SUSE Linux Enterprise Server for SAP Applications 12 SP5 (src): xen-4.12.4_44-3.103.1 SUSE Linux Enterprise High Performance Computing 12 SP5 (src): xen-4.12.4_44-3.103.1 SUSE Linux Enterprise Server 12 SP5 (src): xen-4.12.4_44-3.103.1 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.
SUSE-SU-2024:0264-1: An update that solves one vulnerability can now be installed. Category: security (moderate) Bug References: 1218851 CVE References: CVE-2023-46839 Sources used: openSUSE Leap 15.3 (src): xen-4.14.6_10-150300.3.63.1 SUSE Linux Enterprise High Performance Computing LTSS 15 SP3 (src): xen-4.14.6_10-150300.3.63.1 SUSE Linux Enterprise Server 15 SP3 LTSS 15-SP3 (src): xen-4.14.6_10-150300.3.63.1 SUSE Linux Enterprise Server for SAP Applications 15 SP3 (src): xen-4.14.6_10-150300.3.63.1 SUSE Enterprise Storage 7.1 (src): xen-4.14.6_10-150300.3.63.1 SUSE Linux Enterprise Micro 5.1 (src): xen-4.14.6_10-150300.3.63.1 SUSE Linux Enterprise Micro 5.2 (src): xen-4.14.6_10-150300.3.63.1 SUSE Linux Enterprise Micro for Rancher 5.2 (src): xen-4.14.6_10-150300.3.63.1 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.
Patch submitted for relevant distros.
SUSE-SU-2024:0830-1: An update that solves three vulnerabilities and has one security fix can now be installed. Category: security (moderate) Bug References: 1027519, 1218851, 1219080, 1219885 CVE References: CVE-2023-46839, CVE-2023-46840, CVE-2023-46841 Sources used: openSUSE Leap 15.5 (src): xen-4.17.3_06-150500.3.24.1 SUSE Linux Enterprise Micro 5.5 (src): xen-4.17.3_06-150500.3.24.1 Basesystem Module 15-SP5 (src): xen-4.17.3_06-150500.3.24.1 Server Applications Module 15-SP5 (src): xen-4.17.3_06-150500.3.24.1 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.