btrfs: fix use-after-free when COWing tree bock and tracing is enabled

{
  "id": "665d5f802d3e0e750859d5f437797d0b509fa459cabc9cac3db251faa6406d41",
  "url": "https://osv.dev/vulnerability/CVE-2024-56759",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "btrfs: fix use-after-free when COWing tree bock and tracing is enabled",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free when COWing tree bock and tracing is enabled When a COWing a tree block, at btrfs_cow_block(), and we have the tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled (CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent buffer while inside the tracepoint code. This is because in some paths that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding the last reference on the extent buffer @buf so btrfs_force_cow_block() drops the last reference on the @buf extent buffer when it calls free_extent_buffer_stale(buf), which schedules the release of the extent buffer with RCU. This means that if we are on a kernel with preemption, the current task may be preempted before calling trace_btrfs_cow_block() and the extent buffer already released by the time trace_btrfs_cow_block() is called, resulting in a use-after-free. Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to btrfs_force_cow_block() before the COWed extent buffer is freed. This also has a side effect of invoking the tracepoint in the tree defrag code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is called there, but this is fine and it was actually missing there.",
    "evidence": "osv:CVE-2024-56759",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.233",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.176",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.124",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.70",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.8",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2024-56759",
      "aliases": [
        "CVE-2024-56759"
      ],
      "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": [
                {
                  "introduced": "3083ee2e18b701122a3b841db83448543a87a583"
                },
                {
                  "fixed": "ba5120a2fb5f23b4d39d302e181aa5d4e28a90d1"
                },
                {
                  "fixed": "526ff5b27f090fb15040471f892cd2c9899ce314"
                },
                {
                  "fixed": "66376f1a73cba57fd0af2631d7888605b738e499"
                },
                {
                  "fixed": "9a466b8693b9add05de99af00c7bdff8259ecf19"
                },
                {
                  "fixed": "c3a403d8ce36f5a809a492581de5ad17843e4701"
                },
                {
                  "fixed": "44f52bbe96dfdbe4aca3818a2534520082a07040"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-56759.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "3.4.0"
                },
                {
                  "fixed": "5.10.233"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.176"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.124"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.70"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.8"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-56759.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:41.109645497Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/44f52bbe96dfdbe4aca3818a2534520082a07040",
        "https://git.kernel.org/stable/c/526ff5b27f090fb15040471f892cd2c9899ce314",
        "https://git.kernel.org/stable/c/66376f1a73cba57fd0af2631d7888605b738e499",
        "https://git.kernel.org/stable/c/9a466b8693b9add05de99af00c7bdff8259ecf19",
        "https://git.kernel.org/stable/c/ba5120a2fb5f23b4d39d302e181aa5d4e28a90d1",
        "https://git.kernel.org/stable/c/c3a403d8ce36f5a809a492581de5ad17843e4701",
        "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html",
        "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56759.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-56759",
        "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/2024/56xxx/CVE-2024-56759.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-56759",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 508799,
  "published_at": "2025-01-06T16:20:39.668+00:00"
}