NFSD: Prevent client use-after-free during admin state revocation
In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent client use-after-free during admin state revocation A stateid holds only a bare pointer to its nfs4_client; a stateid reference does not pin it. The client survives only because __destroy_client() drains its stateids before free_client() runs. nfsd4_revoke_states() drops nn->client_lock across revoke_one_stid(), which dereferences the client to revoke a stateid and read clp->cl_minorversion. A teardown racing the dropped lock can free the client first. Pinning cl_rpc_users under client_lock blocks the DESTROY_CLIENTID and EXCHANGE_ID teardown, which refuses while cl_rpc_users is non-zero. force_expire_client() ignores it: once its wait for cl_rpc_users to reach zero has passed, a later pin goes unnoticed. Under client_lock, skip a client whose cl_time is already zero -- force_expire_client() clears it there before waiting -- otherwise pin cl_rpc_users before dropping the lock. The walk then either sees the expiry and skips, or pins in time for that wait to cover the revoke.
CVE-2026-89660
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-2026-89660
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": "1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc",
"lessThan": "e1ba4d3c5bfdca3f013b8cbc829ae2f7975d8608",
"versionType": "git"
},
{
"status": "affected",
"version": "1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc",
"lessThan": "549bd9868e9d77b07ea94870940d64342829c6ad",
"versionType": "git"
},
{
"status": "affected",
"version": "1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc",
"lessThan": "bf1f948691523282cc4905bc6cd325e0c0b49e6a",
"versionType": "git"
},
{
"status": "affected",
"version": "1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc",
"lessThan": "e270e5a0778e5bff852c8862ce9576ce70359393",
"versionType": "git"
}
],
"programFiles": [
"fs/nfsd/nfs4state.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.9",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.51",
"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/nfs4state.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89660
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #35153 · Revision 1
- Added to Heist Feed
- Publisher date