btrfs: send: fix buffer overflow detection when copying path to cache entry

{
  "id": "cff0e708f4c2822d44330c2c7155d51303a93ddb402640eab7b189c1981a04cd",
  "url": "https://osv.dev/vulnerability/CVE-2024-49869",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "btrfs: send: fix buffer overflow detection when copying path to cache entry",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: btrfs: send: fix buffer overflow detection when copying path to cache entry Starting with commit c0247d289e73 (\"btrfs: send: annotate struct name_cache_entry with __counted_by()\") we annotated the variable length array \"name\" from the name_cache_entry structure with __counted_by() to improve overflow detection. However that alone was not correct, because the length of that array does not match the \"name_len\" field - it matches that plus 1 to include the NUL string terminator, so that makes a fortified kernel think there's an overflow and report a splat like this: strcpy: detected buffer overflow: 20 byte write of buffer size 19 WARNING: CPU: 3 PID: 3310 at __fortify_report+0x45/0x50 CPU: 3 UID: 0 PID: 3310 Comm: btrfs Not tainted 6.11.0-prnet #1 Hardware name: CompuLab Ltd. sbc-ihsw/Intense-PC2 (IPC2), BIOS IPC2_3.330.7 X64 03/15/2018 RIP: 0010:__fortify_report+0x45/0x50 Code: 48 8b 34 (...) RSP: 0018:ffff97ebc0d6f650 EFLAGS: 00010246 RAX: 7749924ef60fa600 RBX: ffff8bf5446a521a RCX: 0000000000000027 RDX: 00000000ffffdfff RSI: ffff97ebc0d6f548 RDI: ffff8bf84e7a1cc8 RBP: ffff8bf548574080 R08: ffffffffa8c40e10 R09: 0000000000005ffd R10: 0000000000000004 R11: ffffffffa8c70e10 R12: ffff8bf551eef400 R13: 0000000000000000 R14: 0000000000000013 R15: 00000000000003a8 FS: 00007fae144de8c0(0000) GS:ffff8bf84e780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fae14691690 CR3: 0",
    "evidence": "osv:CVE-2024-49869",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.11.3",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2024-49869",
      "aliases": [
        "CVE-2024-49869"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c0247d289e73e18f6ddb0895de30c09770fbed95"
                },
                {
                  "fixed": "843738ede6cb8b959fb22591fcbabe8b456d7216"
                },
                {
                  "fixed": "96c6ca71572a3556ed0c37237305657ff47174b7"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-49869.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.11.0"
                },
                {
                  "fixed": "6.11.3"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-49869.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:44.855580695Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/843738ede6cb8b959fb22591fcbabe8b456d7216",
        "https://git.kernel.org/stable/c/96c6ca71572a3556ed0c37237305657ff47174b7",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49869.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-49869",
        "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/2024/49xxx/CVE-2024-49869.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-49869",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 512570,
  "published_at": "2024-10-21T18:01:11.389+00:00"
}