Answer in brief
CVE-2026-89686 records a Critical severity (CVSS 9.8) vulnerability in nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), 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.
CVSS is 9.8. 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.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <c517f27498757e616d2a8fe6d16caad1fee422e6 || >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <607a56fea772c1f4f4989d8e255dd4f7192d9604 || >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <97bda8b4284d90897a1f1922e5082ff9e35d7c7e || >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <ca94ba36172046be6a694a7986f6931e47ed4d51 | c517f27498757e616d2a8fe6d16caad1fee422e6, 607a56fea772c1f4f4989d8e255dd4f7192d9604, 97bda8b4284d90897a1f1922e5082ff9e35d7c7e, ca94ba36172046be6a694a7986f6931e47ed4d51 |
| Linux/Linuxgeneric | 4.0 | Not reported |
| Linux/Linuxgeneric | >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <d12af460df27876661707efab3a8532146cb961f || >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <c517f27498757e616d2a8fe6d16caad1fee422e6 || >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <607a56fea772c1f4f4989d8e255dd4f7192d9604 || >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <97bda8b4284d90897a1f1922e5082ff9e35d7c7e || >=c5c707f96fc9a6e5a57ca5baac892673270abe3d <ca94ba36172046be6a694a7986f6931e47ed4d51 | d12af460df27876661707efab3a8532146cb961f, c517f27498757e616d2a8fe6d16caad1fee422e6, 607a56fea772c1f4f4989d8e255dd4f7192d9604, 97bda8b4284d90897a1f1922e5082ff9e35d7c7e, ca94ba36172046be6a694a7986f6931e47ed4d51 |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke nfsd4_alloc_layout_stateid reads fp->fi_deleg_file without holding fi_lock when the parent stateid is a delegation. A concurrent delegation revoke via the laundromat can clear fi_deleg_file under fi_lock, causing nfsd_file_get() to return NULL and triggering the BUG_ON. This race is client-reachable: two NFS clients can trigger it by having one hold a delegation while another opens the same file to force a recall. When the first client doesn't respond to the recall, the laundromat revokes it. A concurrent LAYOUTGET from any client using the delegation stateid hits the race window. Fix this by taking fi_lock around the fi_deleg_file read in the SC_TYPE_DELEG path, matching the locking discipline of the find_any_file() arm, and replacing the BUG_ON with a graceful error return that cleans up the partially-initialized layout stateid.
Quoted source text, attributed separately from HOL analysis.