CVE-2026-98539 affecting package kernel 6.6.157.1-1

{
  "id": "9b98641db92acc95b8b8b3e9a3ddfda4430a1d16986369cb9c8168049e383652",
  "url": "https://osv.dev/vulnerability/AZL-109007",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-98539 affecting package kernel 6.6.157.1-1",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's \"WARNING in do_new_mount\" saga ntfs_create_inode() creates a new inode via ntfs_new_inode(). It hashes it with insert_inode_locked() and so it's marked as I_NEW until unlock_new_inode(). ntfs 3 calls d_instantiate() in between though... Since the dentry was already hashed by the lookup before the create any path walk finds it without touching the parent's i_rwsem and so can lock the inode. If the inode is a directory unlock_new_inode() calls lockdep_annotate_inode_mutex_key() and marks i_rwsem with the i_mutex_dir_key class. That resets the count and the owner of a lock somebody else may already hold by now... syzbot has been spamming us with the same godforsaken bug \"WARNING in do_new_mount\" since 2023. I can't take it anymore so I went looking. Afaict, syzbot's executor chdirs into a freshly mounted ntfs3 image, creates a directory and then mounts some pseudofs on it. Everytime the mkdir() takes longer than syzbot waits mount() runs concurrently: mkdir(\"./sys\") mount(NULL, \"./sys\", \"sysfs\") ntfs_create_inode() d_instantiate() user_path_at() finds the dentry do_lock_mount() inode_lock(inode) namespace_lock() unlock_new_inode() lockdep_annotate_inode_mutex_key() init_rwsem(&inode->i_rwsem) unlock_mount() inode_unlock(inode) The mount side then releases a lock that according to the rwsem nobody holds: DEBUG_RWSEMS_WARN_ON((rwsem_owner",
    "evidence": "osv:AZL-109007",
    "products": [
      {
        "name": {
          "value": "kernel",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "AZL-109007",
      "aliases": [
        "AZL-109007"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "6.6.157.1-1"
                }
              ]
            }
          ],
          "package": {
            "name": "kernel",
            "purl": "pkg:rpm/azure-linux/kernel",
            "ecosystem": "Azure Linux:3"
          },
          "database_specific": {
            "source": "https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-109007.json"
          }
        }
      ],
      "modified": "2026-10-27T05:36:16Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-98539"
      ],
      "references": [
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98539"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-98539",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 460427,
  "published_at": "2026-10-18T16:17:05+00:00"
}