arm64: mm: Fix lockless walks with static and dynamic page-table folding

{
  "id": "942f43582b5903e5aafac922498940df7b96ee8c9d656ab8850b9b5a2a15d1e1",
  "url": "https://osv.dev/vulnerability/CVE-2024-42293",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "arm64: mm: Fix lockless walks with static and dynamic page-table folding",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: arm64: mm: Fix lockless walks with static and dynamic page-table folding Lina reports random oopsen originating from the fast GUP code when 16K pages are used with 4-level page-tables, the fourth level being folded at runtime due to lack of LPA2. In this configuration, the generic implementation of p4d_offset_lockless() will return a 'p4d_t *' corresponding to the 'pgd_t' allocated on the stack of the caller, gup_fast_pgd_range(). This is normally fine, but when the fourth level of page-table is folded at runtime, pud_offset_lockless() will offset from the address of the 'p4d_t' to calculate the address of the PUD in the same page-table page. This results in a stray stack read when the 'p4d_t' has been allocated on the stack and can send the walker into the weeds. Fix the problem by providing our own definition of p4d_offset_lockless() when CONFIG_PGTABLE_LEVELS <= 4 which returns the real page-table pointer rather than the address of the local stack variable.",
    "evidence": "osv:CVE-2024-42293",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.10.3",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2024-42293",
      "aliases": [
        "CVE-2024-42293"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "0dd4f60a2c76938c2625f6c630c225699d97608b"
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                {
                  "fixed": "78672d49d3eebbcda3589f4d6e589caf357c5a59"
                },
                {
                  "fixed": "36639013b3462c06ff8e3400a427f775b4fc97f5"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-42293.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.9.0"
                },
                {
                  "fixed": "6.10.3"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-42293.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.316372488Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/36639013b3462c06ff8e3400a427f775b4fc97f5",
        "https://git.kernel.org/stable/c/78672d49d3eebbcda3589f4d6e589caf357c5a59",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/42xxx/CVE-2024-42293.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-42293",
        "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/2024/42xxx/CVE-2024-42293.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-42293",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496954,
  "published_at": "2024-08-17T09:09:02.303+00:00"
}