DEBIAN-CVE-2023-46835

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    DEBIAN-CVE-2023-46835

    Published: 5 Jan 2024Last Modified: 26 Oct 2026
    Upstream:
    CVE-2023-46835

    Summary:

    Details: The current setup of the quarantine page tables assumes that the quarantine domain (dom_io) has been initialized with an address width of DEFAULT_DOMAIN_ADDRESS_WIDTH (48) and hence 4 page table levels. However dom_io being a PV domain gets the AMD-Vi IOMMU page tables levels based on the maximum (hot pluggable) RAM address, and hence on systems with no RAM above the 512GB mark only 3 page-table levels are configured in the IOMMU. On systems without RAM above the 512GB boundary amd_iommu_quarantine_init() will setup page tables for the scratch page with 4 levels, while the IOMMU will be configured to use 3 levels only, resulting in the last page table directory (PDE) effectively becoming a page table entry (PTE), and hence a device in quarantine mode gaining write access to the page destined to be a PDE. Due to this page table level mismatch, the sink page the device gets read/write access to is no longer cleared between device assignment, possibly leading to data leaks.

    References: https://security-tracker.debian.org/tracker/CVE-2023-46835

    Affected packages

    Package

    Name: xen

    Purl: pkg:deb/debian/xen?arch=source&distro=bookworm

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -4.17.2+76-ge1f9cb16e2-1~deb12u1

    Affected versions

    4.17.1+2-gb773c48e36-1
    4.17.2+55-g0b56bed864-1
    4.17.2-1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    DEBIAN-CVE-2023-46835 | CVE-DB