block: reject bs > ps block devices when THP is disabled

{
  "id": "defcfa532b8715d354780af8cc3b448d6bdf9965676f0ab2a8fbefb687f99b0b",
  "url": "https://osv.dev/vulnerability/CVE-2025-38442",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "block: reject bs > ps block devices when THP is disabled",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: block: reject bs > ps block devices when THP is disabled If THP is disabled and when a block device with logical block size > page size is present, the following null ptr deref panic happens during boot: [ [13.2 mK AOSAN: null-ptr-deref in range [0x0000000000000000-0x0000000000K0 0 0[07] [ 13.017749] RIP: 0010:create_empty_buffers+0x3b/0x380 [ 13.025448] Call Trace: [ 13.025692] [ 13.025895] block_read_full_folio+0x610/0x780 [ 13.026379] ? __pfx_blkdev_get_block+0x10/0x10 [ 13.027008] ? __folio_batch_add_and_move+0x1fa/0x2b0 [ 13.027548] ? __pfx_blkdev_read_folio+0x10/0x10 [ 13.028080] filemap_read_folio+0x9b/0x200 [ 13.028526] ? __pfx_filemap_read_folio+0x10/0x10 [ 13.029030] ? __filemap_get_folio+0x43/0x620 [ 13.029497] do_read_cache_folio+0x155/0x3b0 [ 13.029962] ? __pfx_blkdev_read_folio+0x10/0x10 [ 13.030381] read_part_sector+0xb7/0x2a0 [ 13.030805] read_lba+0x174/0x2c0 [ 13.045348] nvme_scan_ns+0x684/0x850 [nvme_core] [ 13.045858] ? __pfx_nvme_scan_ns+0x10/0x10 [nvme_core] [ 13.046414] ? _raw_spin_unlock+0x15/0x40 [ 13.046843] ? __switch_to+0x523/0x10a0 [ 13.047253] ? kvm_clock_get_cycles+0x14/0x30 [ 13.047742] ? __pfx_nvme_scan_ns_async+0x10/0x10 [nvme_core] [ 13.048353] async_run_entry_fn+0x96/0x4f0 [ 13.048787] process_one_work+0x667/0x10a0 [ 13.049219] worker_thread+0x63c/0xf60 As large folio support depends on THP, only allow bs > ps block devices if THP is enabled.",
    "evidence": "osv:CVE-2025-38442",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.15.7",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2025-38442",
      "aliases": [
        "CVE-2025-38442"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "47dd67532303803a87f43195e088b3b4bcf0454d"
                },
                {
                  "fixed": "b025d81b96bfe8a62b6e3e6ac776608206ccbf6d"
                },
                {
                  "fixed": "4cdf1bdd45ac78a088773722f009883af30ad318"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38442.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.15.0"
                },
                {
                  "fixed": "6.15.7"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38442.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.615520275Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/4cdf1bdd45ac78a088773722f009883af30ad318",
        "https://git.kernel.org/stable/c/b025d81b96bfe8a62b6e3e6ac776608206ccbf6d",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38442.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-38442",
        "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/2025/38xxx/CVE-2025-38442.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-38442",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 513511,
  "published_at": "2025-07-25T15:27:26.009+00:00"
}