nfsd: fix stale s2s_cp_stateids IDR entry for async COPY (CVE-2026-89676) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89676

nfsd: fix stale s2s_cp_stateids IDR entry for async COPY

Answer in brief

CVE-2026-89676 records a Unknown severity vulnerability in nfsd: fix stale s2s_cp_stateids IDR entry for async COPY. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a \|\| >=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <14b978e8d05ce018d0afbeb6611833ef91713a02 \|\| >=e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 <d0beaee498e11880e72826026db0e9c9890fc114	9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a, 14b978e8d05ce018d0afbeb6611833ef91713a02, d0beaee498e11880e72826026db0e9c9890fc114
Linux/Linuxgeneric	4.20	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix stale s2s_cp_stateids IDR entry for async COPY For an async COPY, nfsd4_copy() called nfs4_init_copy_state() before dup_copy_fields(), so the s2s_cp_stateids IDR was pointed at &u->copy->cp_stateid -- memory in the per-rqstp COMPOUND buffer that is reused by the next request. dup_copy_fields() copies only the value into async_copy, so the IDR slot dangled at the transient buffer for the whole background copy. Any IDR walker then dereferences reused request memory: the laundromat reads cs_type from it and, if the bytes look like an expired NFS4_COPYNOTIFY_STID, follows into refcount_dec()/idr_remove()/kfree() on garbage; manage_cpntf_state() has the same exposure via idr_find(). Duplicate the fields first, then register the stateid on the stable async_copy. result->cb_stateid is unchanged.

Quoted source text, attributed separately from HOL analysis.