CVE-2025-40146: blk-mq: fix potential deadlock while nr_requests grown

mediumCVSS 6.2CVE-2025-40146

CSIRTS triage

vendor: Linux product: Linux Kernel Denial of service

What: A potential deadlock in the block I/O request queue handling when the nr_requests parameter is increased.
Who is affected: Systems running affected Linux kernel versions with dynamic request queue resizing.
Urgency: Medium priority; not actively exploited but can cause service disruption through deadlock.
Action: Update to a patched Linux kernel version that fixes the deadlock condition in blk-mq.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 6.2
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-40146

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2025-401460.22% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 13% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2025-40146	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[UPDATE] [high] Linux Kernel: Multiple vulnerabilitiescert-bund

Recent advisories for blk-mq

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-64017: In the Linux kernel, the following vulnerability has been resolved: blk-mq: pop cached request…nvd · 2026-07-19
criticalCVE-2026-64017: blk-mq: pop cached request if it is usablemsrc · 2026-07-14