CVE-2025-40105vfs: Don't leak disconnected dentries on umount

Description

In the Linux kernel, the following vulnerability has been resolved: vfs: Don't leak disconnected dentries on umount When user calls open_by_handle_at() on some inode that is not cached, we will create disconnected dentry for it. If such dentry is a directory, exportfs_decode_fh_raw() will then try to connect this dentry to the dentry tree through reconnect_path(). It may happen for various reasons (such as corrupted fs or race with rename) that the call to lookup_one_unlocked() in reconnect_one() will fail to find the dentry we are trying to reconnect and instead create a new dentry under the parent. Now this dentry will not be marked as disconnected although the parent still may well be disconnected (at least in case this inconsistency happened because the fs is corrupted and .. doesn't point to the real parent directory). This creates inconsistency in disconnected flags but AFAICS it was mostly harmless. At least until commit f1ee616214cb ("VFS: don't keep disconnected dentries on d_anon") which removed adding of most disconnected dentries to sb->s_anon list. Thus after this commit cleanup of disconnected dentries implicitely relies on the fact that dput() will immediately reclaim such dentries. However when some leaf dentry isn't marked as disconnected, as in the scenario described above, the reclaim doesn't happen and the dentries are "leaked". Memory reclaim can eventually reclaim them but otherwise they stay in memory and if umount comes first, we hit infamous "Busy inodes after unmount" bug. Make sure all dentries created under a disconnected parent are marked as disconnected as well.

Timeline

Scores

EPSS (exploitation in 30 days)

0.17% · top 94% of all CVEs (12 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Linux · Linux

  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < b5abafd0aa8d7bcb935c8f91e4cfc2f2820759e4
  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < 20863bb7fbb016379f8227122edfabc5c799bc79
  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < 8004d4b8cbf1bd68a23c160d57287e177c82cc69
  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < 7e0c8aaf4e28918abded547a5147c7d52c4af7d2
  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < cebfbf40056a4d858b2a3ca59a69936d599bd209
  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < 620f3b0ede9c5cb4976cd0457d0b04ad551e5d6b
  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < eadc49999fa994d6fbd70c332bd5d5051cc42261
  • affected f1ee616214cb22410e939d963bbb2349c2570f02 – < 56094ad3eaa21e6621396cc33811d8f72847a834

• Linux · Linux

  • affected 4.16
  • unaffected < 4.16
  • unaffected 5.4.301 – ≤ 5.4.*
  • unaffected 5.10.246 – ≤ 5.10.*
  • unaffected 5.15.196 – ≤ 5.15.*
  • unaffected 6.1.158 – ≤ 6.1.*
  • unaffected 6.6.114 – ≤ 6.6.*
  • unaffected 6.12.55 – ≤ 6.12.*
  • unaffected 6.17.5 – ≤ 6.17.*
  • unaffected 6.18 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2025-36973 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2025-40105](https://cveledger.app/badge/CVE-2025-40105.svg)](https://cveledger.app/cve/CVE-2025-40105)

Record last updated 10 Nov 2026, 12:37 UTC.