nfsd: release path refs on follow_down() error
In the Linux kernel, the following vulnerability has been resolved: nfsd: release path refs on follow_down() error nfsd_cross_mnt() initializes a local struct path with mntget() and dget() before calling follow_down(). On a negative return the error arm jumps to out without releasing those references: err = follow_down(&path, follow_flags); if (err < 0) goto out; follow_down() never drops the caller's entry-time refs on any error sub-case; for example a pre-cross d_manage() failure leaves path untouched, so the mntget()/dget() taken on entry survive the call. Every other early-exit arm in nfsd_cross_mnt() (other-namespace return, IS_ERR(exp2), and the success tail after the swap) already calls path_put(&path); the err < 0 arm is the lone omission. The leak inflates mnt_count and d_count on each failed cross-mount, blocking umount and pinning dentries against the shrinker, and is reachable by any authenticated NFS client through nfsd_lookup_dentry or the NFSv4 READDIR encode path. Fix by calling path_put(&path) before the goto out in the err < 0 arm so the entry-time refs are released on all follow_down() error returns.
CVE-2026-89707
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-2026-89707
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": "cc53ce53c86924bfe98a12ea20b7465038a08792",
"lessThan": "085cfde7c2186acaad103f02d2c25435ad5224e9",
"versionType": "git"
},
{
"status": "affected",
"version": "cc53ce53c86924bfe98a12ea20b7465038a08792",
"lessThan": "194316df81263519156ebe714c4a286bee00e5be",
"versionType": "git"
},
{
"status": "affected",
"version": "cc53ce53c86924bfe98a12ea20b7465038a08792",
"lessThan": "467d56fd3ff57447a790c6dc3ede2d02a947d224",
"versionType": "git"
},
{
"status": "affected",
"version": "cc53ce53c86924bfe98a12ea20b7465038a08792",
"lessThan": "2bc4343308d85ee4e0dd3877b384306c96f114c2",
"versionType": "git"
},
{
"status": "affected",
"version": "cc53ce53c86924bfe98a12ea20b7465038a08792",
"lessThan": "6cba08dc1922140d260cfeb30bbda4ee1bf869d8",
"versionType": "git"
}
],
"programFiles": [
"fs/nfsd/vfs.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.38"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.38",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/nfsd/vfs.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89707
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35188 · Revision 1
- Added to Heist Feed
- Publisher date