{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "b709eb872e19a19607bbb6d2975bc264d59735cf"
            },
            {
              "fixed": "c8b7e113f7b61eef2f017e6329c27c2331058c5a"
            },
            {
              "fixed": "0cff05bd2186020f8706233e261016d149cc24db"
            },
            {
              "fixed": "5948aaf64f81f217a25dcc2bf6c0779bca19566c"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.14.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64300.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/aux: Fix page UAF in map_range()\n\nmap_range() reads rb-\u003eaux_pages[], rb-\u003eaux_nr_pages and rb-\u003eaux_pgoff via\nperf_mmap_to_page() while holding only event-\u003emmap_mutex. Those fields are\nserialized by rb-\u003eaux_mutex, and mmap_mutex is per event.\n\nThus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race\nrb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows:\n\n  CPU 0                           CPU 1\n  =====                           =====\n  rb_alloc_aux()                  map_range()\n  [1]: allocate rb-\u003eaux_pages[0]\n  [2]: rb-\u003eaux_nr_pages++\n                                  [3]: perf_mmap_to_page()\n                                         returns rb-\u003eaux_pages[0]\n                                  [4]: map it as VM_PFNMAP\n  [5]: rb-\u003eaux_pgoff = 1\n\n  munmap the page\n  [6]: free rb-\u003eaux_pages[0]\n\nPages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a\nmapping to a freed physical frame.\n\nFix this by taking rb-\u003eaux_mutex across the page walk in map_range().",
  "id": "CVE-2026-64300",
  "modified": "2026-07-27T03:56:39.526764572Z",
  "published": "2026-07-25T08:49:36.372Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0cff05bd2186020f8706233e261016d149cc24db"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5948aaf64f81f217a25dcc2bf6c0779bca19566c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c8b7e113f7b61eef2f017e6329c27c2331058c5a"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64300.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64300"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "perf/aux: Fix page UAF in map_range()"
}