cachefiles: fix dentry leak in cachefiles_open_file()

{
  "id": "3a7ab81dc04923cf4066bc189337f9cc58e69b60c992f45b7a06e22dcb247560",
  "url": "https://osv.dev/vulnerability/CVE-2024-49870",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "cachefiles: fix dentry leak in cachefiles_open_file()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix dentry leak in cachefiles_open_file() A dentry leak may be caused when a lookup cookie and a cull are concurrent: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // get dentry cachefiles_cull inode->i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode->i_flags & S_KERNEL_FILE)) can_use = true return false return false // Returns an error but doesn't put dentry After that the following WARNING will be triggered when the backend folder is umounted: ================================================================== BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda] WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Call Trace: d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ================================================================== Whether cachefiles_open_file() returns true or false, the reference count obtained by lookup_positive_unlocked() in cachefiles_look_up_object() should be released. There",
    "evidence": "osv:CVE-2024-49870",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.113",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.55",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.10.14",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.11.3",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2024-49870",
      "aliases": [
        "CVE-2024-49870"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1f08c925e7a38002bde509e66f6f891468848511"
                },
                {
                  "fixed": "d32ff64c872d7e08e893c32ba6a2374583444410"
                },
                {
                  "fixed": "c7d10fa7d7691558ff967668494672415f5fa151"
                },
                {
                  "fixed": "e4a28489b310339b2b8187bec0a437709be551c1"
                },
                {
                  "fixed": "7fa2382f97421978514a419c93054eca69f5247b"
                },
                {
                  "fixed": "da6ef2dffe6056aad3435e6cf7c6471c2a62187c"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-49870.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.17.0"
                },
                {
                  "fixed": "6.1.113"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.55"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.10.14"
                }
              ]
            },
            {
              "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-2024-49870.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:44.698626252Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b",
        "https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151",
        "https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410",
        "https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c",
        "https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1",
        "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49870.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-49870",
        "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-2024-49870.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-49870",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 512651,
  "published_at": "2024-10-21T18:01:12.048+00:00"
}