CVE-2026-23100

Linux kernel (Xilinx) vulnerabilities

mediumEPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix hugetlb_pmd_shared() Patch series "mm/hugetlb: fixes for PMD table sharing (incl. using mmu_gather)", v3. One functional fix, one performance regression fix, and two related comment fixes. I cleaned up my prototype I recently shared [1] for the performance fix, deferring most of the cleanups I had in the prototype to a later point. While doing that I identified the other things. The goal of this patch set is to be backported to stable trees "fairly" easily. At least patch #1 and #4. Patch #1 fixes hugetlb_pmd_shared() not detecting any sharing Patch #2 + #3 are simple comment fixes that patch #4 interacts with. Patch #4 is a fix for the reported performance regression due to excessive IPI broadcasts during fork()+exit(). The last patch is all about TLB flushes, IPIs and mmu_gather. Read: complicated There are plenty of cleanups in the future to be had + one reasonable optimization on x86. But that's all out of scope for this series. Runtime tested, with a focus on fixing the performance regression using the original reproducer [2] on x86. This patch (of 4): We switched from (wrongly) using the page count to an independent shared count. Now, shared page tables have a refcount of 1 (excluding speculative references) and instead use ptdesc->pt_share_count to identify sharing. We didn't convert hugetlb_pmd_shared(), so right now, we would never detect a shared PMD table as such, because sharing/unsharing no longer touches the refcount of a PMD table. Page migration, like mbind() or migrate_pages() would allow for migrating folios mapped into such shared PMD tables, even though the folios are not exclusive. In smaps we would account them as "private" although they are "shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the pagemap interface. Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared().

Metrics

Severity
medium
no public PoC known
5.5
Source: nvd-v3
2.5 %
Low — this CVE sits in the lower 10% of all CVEs scored today.
0.1 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-07-02 15:56 UTC

Affected operating systems

  • linux

    amazon / amazon_linux

  • linux

    ubuntu / awsbionic

  • linux

    ubuntu / awsjammy

  • linux

    ubuntu / awsnoble

  • linux

    ubuntu / awsresolute

  • linux

    ubuntu / awsxenial

  • linux

    ubuntu / aws-6.8jammy

  • linux

    ubuntu / aws-hwexenial

  • linux

    ubuntu / azurejammy

  • linux

    ubuntu / azurenoble

  • linux

    ubuntu / azureresolute

  • linux

    ubuntu / azurexenial

  • linux

    ubuntu / azure-4.15bionic

  • linux

    suse / basesystem_module15

  • linux

    debian / debian_linux11.0

  • linux

    debian / debian_linux12.0

  • linux

    debian / debian_linux13.0

  • linux

    suse / development_tools_module15

  • linux

    redhat / enterprise_linux10.0

  • linux

    redhat / enterprise_linux8.0

  • linux

    redhat / enterprise_linux9.0

  • linux

    redhat / enterprise_linux_aus8.4

  • linux

    redhat / enterprise_linux_aus8.6

  • linux

    redhat / enterprise_linux_eus10.0

Affected products

Products and version ranges extracted from the vendor/CERT advisory. A range like „<4.14.6“ implies the update recommendation „upgrade to 4.14.6 or later“.

  • arista

    cloudvision_agni2024.4.0 – 2025.2.2

  • arista

    cloudvision_portal2024.2.0 – 2026.1.0

  • arista

    velocloud_edge4.5.0 – 6.4.1

  • arista

    velocloud_gateway

  • arista

    velocloud_orchestrator

  • IBM

    QRadar SIEM<7.5.0 UP15 IF06

  • redhat

    openshift_container_platform4.12 – 4.12.89

  • redhat

    openshift_container_platform4.13 – 4.13.66

  • redhat

    openshift_container_platform4.14 – 4.14.65

  • redhat

    openshift_container_platform4.15 – 4.15.64

  • redhat

    openshift_container_platform4.16 – 4.16.61

  • redhat

    openshift_container_platform4.17 – 4.17.53

  • redhat

    openshift_container_platform4.18 – 4.18.40

  • redhat

    openshift_container_platform4.19 – 4.19.30

  • redhat

    openshift_container_platform4.20 – 4.20.21

  • redhat

    openshift_container_platform4.21 – 4.21.14

  • redhat

    openshift_container_platform

  • siemens

    simatic_ax_runtime

  • suse

    caas_platform

  • suse

    enterprise_storage

  • suse

    manager_proxy

  • suse

    manager_retail_branch_server

  • suse

    manager_server

  • suse

    openstack_cloud

References & sources

Linked CVEs

Show 491 more CVEs
IDCVE-2026-23100
Linux kernel (Xilinx) vulnerabilities — CVE-2026-23100 | NEOSEC Intel