{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7fbb5e188248c50f737720825da1864ce42536d1"
            },
            {
              "fixed": "08de46a75f91a6661bc1ce0a93614f4bc313c581"
            },
            {
              "fixed": "0524ee56af2c9bfbad152a810f1ca95de8ca00d7"
            },
            {
              "fixed": "f6fa05f0dddd387417d0c28281ddb951582514d6"
            },
            {
              "fixed": "dd085fe9a8ebfc5d10314c60452db38d2b75e609"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.8.0"
            },
            {
              "fixed": "6.12.78"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.17"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23375.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: thp: deny THP for files on anonymous inodes\n\nfile_thp_enabled() incorrectly allows THP for files on anonymous inodes\n(e.g. guest_memfd and secretmem). These files are created via\nalloc_file_pseudo(), which does not call get_write_access() and leaves\ninode-\u003ei_writecount at 0. Combined with S_ISREG(inode-\u003ei_mode) being\ntrue, they appear as read-only regular files when\nCONFIG_READ_ONLY_THP_FOR_FS is enabled, making them eligible for THP\ncollapse.\n\nAnonymous inodes can never pass the inode_is_open_for_write() check\nsince their i_writecount is never incremented through the normal VFS\nopen path. The right thing to do is to exclude them from THP eligibility\naltogether, since CONFIG_READ_ONLY_THP_FOR_FS was designed for real\nfilesystem files (e.g. shared libraries), not for pseudo-filesystem\ninodes.\n\nFor guest_memfd, this allows khugepaged and MADV_COLLAPSE to create\nlarge folios in the page cache via the collapse path, but the\nguest_memfd fault handler does not support large folios. This triggers\nWARN_ON_ONCE(folio_test_large(folio)) in kvm_gmem_fault_user_mapping().\n\nFor secretmem, collapse_file() tries to copy page contents through the\ndirect map, but secretmem pages are removed from the direct map. This\ncan result in a kernel crash:\n\n    BUG: unable to handle page fault for address: ffff88810284d000\n    RIP: 0010:memcpy_orig+0x16/0x130\n    Call Trace:\n     collapse_file\n     hpage_collapse_scan_file\n     madvise_collapse\n\nSecretmem is not affected by the crash on upstream as the memory failure\nrecovery handles the failed copy gracefully, but it still triggers\nconfusing false memory failure reports:\n\n    Memory failure: 0x106d96f: recovery action for clean unevictable\n    LRU page: Recovered\n\nCheck IS_ANON_FILE(inode) in file_thp_enabled() to deny THP for all\nanonymous inode files.",
  "id": "CVE-2026-23375",
  "modified": "2026-04-01T23:09:31.572889176Z",
  "published": "2026-03-25T10:27:55.754Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0524ee56af2c9bfbad152a810f1ca95de8ca00d7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/08de46a75f91a6661bc1ce0a93614f4bc313c581"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dd085fe9a8ebfc5d10314c60452db38d2b75e609"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f6fa05f0dddd387417d0c28281ddb951582514d6"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23375.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23375"
    }
  ],
  "schema_version": "1.7.3",
  "summary": "mm: thp: deny THP for files on anonymous inodes"
}