md: remove REQ_NOWAIT support from raid1/10/456

Answer in brief

CVE-2026-90401 records a Unknown severity vulnerability in md: remove REQ_NOWAIT support from raid1/10/456. 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 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 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	>=f51d46d0e7cb5b8494aa534d276a9d8915a2443d <9bb9504e2d8f3d22ef12d51c333dd499f402dc8f \|\| >=f51d46d0e7cb5b8494aa534d276a9d8915a2443d <3fe5b7c9fb72ccc29bfd0f955b124892af7e3674 \|\| 39db562b3fedb93978a7e42dd216b306740959f8 \|\| >=5.15.111 <5.16	9bb9504e2d8f3d22ef12d51c333dd499f402dc8f, 3fe5b7c9fb72ccc29bfd0f955b124892af7e3674, 5.16
Linux/Linuxgeneric	5.17	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 9bb9504e2d8f3d22ef12d51c333dd499f402dc8f if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: md: remove REQ_NOWAIT support from raid1/10/456 REQ_NOWAIT support in md personalities that can block internally is fundamentally incomplete. While reads can avoid some blocking paths, write requests can still encounter cases where one mirror succeeds while another returns -EAGAIN. At that point md cannot distinguish queue pressure from a real device failure, so it can neither record a bad block nor safely retry the write without REQ_NOWAIT, leaving mirrors with divergent data. Rather than continue advertising REQ_NOWAIT support for personalities that cannot implement it correctly, remove it from raid1, raid10 and raid456. Keep REQ_NOWAIT for linear and raid0, which only remap bios to their underlying devices; stacked limits will still clear the feature if any component device lacks REQ_NOWAIT support.

Quoted source text, attributed separately from HOL analysis.