ovl: fix UAF in ovl_do_mkdir() debug print

{
  "id": "39d0d0e51e649200f72bc71398844da855c5ee688e946218636b1d3e902a8615",
  "url": "https://osv.dev/vulnerability/CVE-2026-98921",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ovl: fix UAF in ovl_do_mkdir() debug print",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ovl: fix UAF in ovl_do_mkdir() debug print ovl_do_mkdir() prints the input dentry with %pd after vfs_mkdir(). Since commit fe497f0759e0 (\"VFS: change vfs_mkdir() to unlock on failure.\"), vfs_mkdir() calls end_creating() on the input dentry on failure and may replace it on success, so the post-call %pd can use-after-free the dentry when CONFIG_OVERLAY_FS_DEBUG is enabled. Print the dentry before the call and only the result afterward.",
    "evidence": "osv:CVE-2026-98921",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.2.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98921",
      "aliases": [
        "CVE-2026-98921"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "fe497f0759e0efb949f9480911d00b6045c21f50"
                },
                {
                  "fixed": "719bd33ab359c539a68a278c15a97deb77565cdb"
                },
                {
                  "fixed": "ae146bc1abdeb4607abf2975b858c053024e8ac1"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98921.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.9"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98921.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:31.931769185Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/719bd33ab359c539a68a278c15a97deb77565cdb",
        "https://git.kernel.org/stable/c/ae146bc1abdeb4607abf2975b858c053024e8ac1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98921.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98921",
        "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/2026/98xxx/CVE-2026-98921.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98921",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 499159,
  "published_at": "2026-10-23T12:02:38.969+00:00"
}