{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "63a5c7a4b4c49ad86c362e9f555e6f343804ee1d"
            },
            {
              "fixed": "9525e3a6fbb1d126a22ab2ee86ddea25af581a7c"
            },
            {
              "fixed": "7c89f474005d8377525d2991930b7432ee193a52"
            },
            {
              "fixed": "b35a13036755c5803168a7cb93bc66035c3e65b8"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.34"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64071.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-pci: fix use-after-free in nvme_free_host_mem()\n\nnvme_free_host_mem() frees dev-\u003ehmb_sgt via dma_free_noncontiguous()\nbut never clears the pointer afterward.  This leads to a use-after-free\nif nvme_free_host_mem() is called twice in the same error path.\n\nThis can happen during nvme_probe() when nvme_setup_host_mem() succeeds\nin allocating the HMB (setting dev-\u003ehmb_sgt) but nvme_set_host_mem()\nfails with an I/O error:\n\n  nvme_setup_host_mem()\n    nvme_alloc_host_mem_single()   -\u003e sets dev-\u003ehmb_sgt\n    nvme_set_host_mem()            -\u003e fails with -EIO\n    nvme_free_host_mem()           -\u003e frees hmb_sgt, but does NOT NULL it\n    return error\n\n  nvme_probe() error path:\n    nvme_free_host_mem()           -\u003e dev-\u003ehmb_sgt is stale, use-after-free\n\nThe second call dereferences the freed sgt, causing a NULL pointer\ndereference in iommu_dma_free_noncontiguous() when it accesses\nsgt-\u003esgl-\u003edma_address (the backing memory has been freed and zeroed).\n\nThis is reproducible on Thunderbolt-attached NVMe devices (e.g., OWC\nEnvoy Express behind a Dell WD22TB4 dock) where the device intermittently\nreturns I/O errors during HMB setup due to PCIe link instability.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000010\n RIP: 0010:iommu_dma_free_noncontiguous+0x22/0x80\n Call Trace:\n  \u003cTASK\u003e\n  dma_free_noncontiguous+0x3b/0x130\n  nvme_free_host_mem+0x30/0xf0 [nvme]\n  nvme_probe.cold+0xcc/0x275 [nvme]\n  local_pci_probe+0x43/0xa0\n  pci_device_probe+0xeea/0x290\n  really_probe+0xf9/0x3b0\n  __driver_probe_device+0x8b/0x170\n  driver_probe_device+0x24/0xd0\n  __driver_attach_async_helper+0x6b/0x110\n  async_run_entry_fn+0x37/0x170\n  process_one_work+0x1ac/0x3d0\n  worker_thread+0x1b8/0x360\n  kthread+0xf7/0x130\n  ret_from_fork+0x2d8/0x3a0\n  ret_from_fork_asm+0x1a/0x30\n  \u003c/TASK\u003e\n\nFix this by setting dev-\u003ehmb_sgt to NULL after freeing it, so the\nsecond call takes the multi-descriptor path which safely handles the\nalready-cleaned-up state.",
  "id": "CVE-2026-64071",
  "modified": "2026-07-21T03:41:51.347903998Z",
  "published": "2026-07-19T15:39:47.162Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7c89f474005d8377525d2991930b7432ee193a52"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9525e3a6fbb1d126a22ab2ee86ddea25af581a7c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b35a13036755c5803168a7cb93bc66035c3e65b8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64071.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64071"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "nvme-pci: fix use-after-free in nvme_free_host_mem()"
}