sunrpc: defer rq_argp and rq_resp free until after RCU grace period (CVE-2026-89545) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89545

sunrpc: defer rq_argp and rq_resp free until after RCU grace period

Answer in brief

CVE-2026-89545 records a Unknown severity vulnerability in sunrpc: defer rq_argp and rq_resp free until after RCU grace period. 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	>=812443865c5fc255363d4a684a62c086af1addca <08bc49e0541260bf294962cf889a32a2d2713ad6 \|\| >=812443865c5fc255363d4a684a62c086af1addca <e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090 \|\| >=812443865c5fc255363d4a684a62c086af1addca <c479bde671cbe2f9e152834a8b0eb7c3c295bbaf	08bc49e0541260bf294962cf889a32a2d2713ad6, e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090, c479bde671cbe2f9e152834a8b0eb7c3c295bbaf
Linux/Linuxgeneric	3.19	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 08bc49e0541260bf294962cf889a32a2d2713ad6 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: sunrpc: defer rq_argp and rq_resp free until after RCU grace period svc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously via kfree(), but defers the rqstp struct free via kfree_rcu(). After svc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is a window where RCU readers that started before list_del_rcu() can still traverse the thread list and find the rqstp. These readers (e.g. nfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has already been freed — a use-after-free. Fix this by moving the kfree of rq_argp and rq_resp into an explicit call_rcu() callback alongside the struct free. Resources not accessed by RCU readers (bvec, buffer pages, scratch folio, auth_data) remain synchronously freed.

Quoted source text, attributed separately from HOL analysis.