dlm: fix add msg handle in send_queue ordered

Answer in brief

CVE-2026-74401 records a Critical severity (CVSS 9.8) vulnerability in dlm: fix add msg handle in send_queue ordered. 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 Aug 15, 2026Updated Aug 17, 2026Source checked Sep 29, 2026First seen by HOL Aug 15, 2026Material review Aug 17, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

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.

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	>=489d8e559c6596eb08e16447d9830bc39afbe54e <ae9e534e502a0f48c12baf83608c5de0ff0eab11 \|\| >=489d8e559c6596eb08e16447d9830bc39afbe54e <6369619f1b665f12d8c99cc6ff733c64eb08b22e \|\| >=489d8e559c6596eb08e16447d9830bc39afbe54e <712714f818d83373847874ab0f8e426be79296cf \|\| >=489d8e559c6596eb08e16447d9830bc39afbe54e <4d45250b1d22960f86d83245be188b16e456218b \|\| >=489d8e559c6596eb08e16447d9830bc39afbe54e <d2248cb70c070f8f04762872772e155b59016f17	ae9e534e502a0f48c12baf83608c5de0ff0eab11, 6369619f1b665f12d8c99cc6ff733c64eb08b22e, 712714f818d83373847874ab0f8e426be79296cf, 4d45250b1d22960f86d83245be188b16e456218b, d2248cb70c070f8f04762872772e155b59016f17
Linux/Linuxgeneric	5.14	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to ae9e534e502a0f48c12baf83608c5de0ff0eab11 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 15, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: dlm: fix add msg handle in send_queue ordered In a benchmark scenario triggering a lot of requests that triggers a lot of DLM messages on the network it can be that the mh->seq is not ordered according the oldest seq number. This ordering is required by dlm_receive_ack as "before(mh->seq, seq)" will stop to check for older sequence numbers that are ordered in the tail of "node->send_queue". The side effects of not having it correct ordered regarding "before(mh->seq, seq)" are refcounting issues and use-after free. I only was able to reproduce this issue in a experimental DLM branch and a user space DLM benchmark that uses io_uring. After changing this I don't experienced any refcounting with the sending buffer issues anymore.

Quoted source text, attributed separately from HOL analysis.