irqchip/gic-v3-its: Avoid truncating memory addresses

{
  "id": "654fc005decdbd40858a0559aeb7cc88566a3ebf1a57571137cdc92816d3db9d",
  "url": "https://osv.dev/vulnerability/CVE-2026-23085",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "irqchip/gic-v3-its: Avoid truncating memory addresses",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v3-its: Avoid truncating memory addresses On 32-bit machines with CONFIG_ARM_LPAE, it is possible for lowmem allocations to be backed by addresses physical memory above the 32-bit address limit, as found while experimenting with larger VMSPLIT configurations. This caused the qemu virt model to crash in the GICv3 driver, which allocates the 'itt' object using GFP_KERNEL. Since all memory below the 4GB physical address limit is in ZONE_DMA in this configuration, kmalloc() defaults to higher addresses for ZONE_NORMAL, and the ITS driver stores the physical address in a 32-bit 'unsigned long' variable. Change the itt_addr variable to the correct phys_addr_t type instead, along with all other variables in this driver that hold a physical address. The gicv5 driver correctly uses u64 variables, while all other irqchip drivers don't call virt_to_phys or similar interfaces. It's expected that other device drivers have similar issues, but fixing this one is sufficient for booting a virtio based guest.",
    "evidence": "osv:CVE-2026-23085",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
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    "severity": "unknown",
    "structured": {
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      "aliases": [
        "CVE-2026-23085"
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            "ecosystem": "Linux"
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      ],
      "modified": "2026-10-28T02:30:49.641542073Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/03faa61eb4b9ca9aa09bd91d4c3773d8e7b1ac98",
        "https://git.kernel.org/stable/c/084ba3b99f2dfd991ce7e84fb17117319ec3cd9f",
        "https://git.kernel.org/stable/c/1b323391560354d8c515de8658b057a1daa82adb",
        "https://git.kernel.org/stable/c/85215d633983233809f7d4dad163b953331b8238",
        "https://git.kernel.org/stable/c/8d76a7d89c12d08382b66e2f21f20d0627d14859",
        "https://git.kernel.org/stable/c/e2f9c751f73a2d5bb62d94ab030aec118a811f27",
        "https://git.kernel.org/stable/c/e332b3b69e5b3acf07204a4b185071bab15c2b88",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23085.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-23085",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23085.json"
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    },
    "related_cves": [
      {
        "value": "CVE-2026-23085",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 518117,
  "published_at": "2026-02-04T16:08:09.368+00:00"
}