mm/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy()

{
  "id": "e9a5144dda5fdb79dcf0ae0892e9ea2498fd7bf04ec80ac81f5fd4c9295b4754",
  "url": "https://osv.dev/vulnerability/CVE-2024-57881",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "mm/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: mm/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy() In split_large_buddy(), we might call pfn_to_page() on a PFN that might not exist. In corner cases, such as when freeing the highest pageblock in the last memory section, this could result with CONFIG_SPARSEMEM && !CONFIG_SPARSEMEM_EXTREME in __pfn_to_section() returning NULL and and __section_mem_map_addr() dereferencing that NULL pointer. Let's fix it, and avoid doing a pfn_to_page() call for the first iteration, where we already have the page. So far this was found by code inspection, but let's just CC stable as the fix is easy.",
    "evidence": "osv:CVE-2024-57881",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.7",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2024-57881",
      "aliases": [
        "CVE-2024-57881"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "fd919a85cd55be5d00a6a7372071f44c8eafb825"
                },
                {
                  "fixed": "4234ca9884bcae9e48ed38652d91696ad5cd591d"
                },
                {
                  "fixed": "faeec8e23c10bd30e8aa759a2eb3018dae00f924"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-57881.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.10.0"
                },
                {
                  "fixed": "6.12.7"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-57881.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.607686303Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/4234ca9884bcae9e48ed38652d91696ad5cd591d",
        "https://git.kernel.org/stable/c/faeec8e23c10bd30e8aa759a2eb3018dae00f924",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/57xxx/CVE-2024-57881.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-57881",
        "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/2024/57xxx/CVE-2024-57881.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-57881",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504590,
  "published_at": "2025-01-11T15:10:43.786+00:00"
}