vfs: Don't leak disconnected dentries on umount
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 ino
CVE-2025-40105
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-40105
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "b5abafd0aa8d7bcb935c8f91e4cfc2f2820759e4",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "20863bb7fbb016379f8227122edfabc5c799bc79",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "8004d4b8cbf1bd68a23c160d57287e177c82cc69",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "7e0c8aaf4e28918abded547a5147c7d52c4af7d2",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "cebfbf40056a4d858b2a3ca59a69936d599bd209",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "620f3b0ede9c5cb4976cd0457d0b04ad551e5d6b",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "eadc49999fa994d6fbd70c332bd5d5051cc42261",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ee616214cb22410e939d963bbb2349c2570f02",
"lessThan": "56094ad3eaa21e6621396cc33811d8f72847a834",
"versionType": "git"
}
],
"programFiles": [
"fs/dcache.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.4.301",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.246",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.196",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.158",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.114",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.55",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.17.5",
"versionType": "semver",
"lessThanOrEqual": "6.17.*"
},
{
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/dcache.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-40105
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30674 · Revision 1
- Added to Heist Feed
- Publisher date