Unknown

CVE-2025-40125 — blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx

In the Linux kernel, the following vulnerability has been resolved: blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx In __blk_mq_update_nr_hw_queues() the return value of blk_mq_sysfs_register_hctxs() is not checked. If sysfs creation for hctx fails, later changing the number of hw_queues or removing disk will trigger the following warning: kernfs: can not remove 'nr_tags', no directory WARNING: CPU: 2 PID: 637 at fs/kernfs/dir.c:1707 kernfs_remove_by_name_ns+0x13f/0x160 Call Trace: remove_files.isra.1+0x38/0xb0 sysfs_remove_group+0x4d/0x100 sysfs_remove_groups+0x31/0x60 __kobject_del+0x23/0xf0 kobject_del+0x17/0x40 blk_mq_unregister_hctx+0x5d/0x80 blk_mq_sysfs_unregister_hctxs+0x94/0xd0 blk_mq_update_nr_hw_queues+0x124/0x760 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_submit_queues_store+0x92/0x120 [null_blk] kobjct_del() was called unconditionally even if sysfs creation failed. Fix it by checkig the kobject creation statusbefore deleting it.

Published Nov 12, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.23%

ahead of 12% of scored CVEs · Oct 14, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < a8c53553f1833cc2d14175d2d72cf37193a01898≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < cc14ea21c4e658814d737ed4dedde6cd626a15ad≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < 4b97e99b87a773d52699521d40864f3ec888e9a6≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < 6e7dadc5763c48eb3b9b91265a21f312599ebb2c≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < 06c4826b1d900611096e4621e93133db57e13911≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < babc634e9fe2803962dba98a07587e835dbc0731≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < d5ddd76ee52bdc16e9f8b1e7791291e785dab032≥ 477e19dedc9d3e1f4443a1d4ae00572a988120ea and < 4c7ef92f6d4d08a27d676e4c348f4e2922cab3ed and 1 more version 4.20	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.23%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 13, 2026
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Deferred
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2025
CVE published
Nov 12, 2025 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

8 on the record

git.kernel.org/stable/c/6e7dadc5763c48eb3b9b91265a21f312599ebb2c
NIST National Vulnerability Database
git.kernel.org/stable/c/4c7ef92f6d4d08a27d676e4c348f4e2922cab3ed
NIST National Vulnerability Database
git.kernel.org/stable/c/06c4826b1d900611096e4621e93133db57e13911
NIST National Vulnerability Database
git.kernel.org/stable/c/babc634e9fe2803962dba98a07587e835dbc0731
NIST National Vulnerability Database
git.kernel.org/stable/c/d5ddd76ee52bdc16e9f8b1e7791291e785dab032
NIST National Vulnerability Database
git.kernel.org/stable/c/a8c53553f1833cc2d14175d2d72cf37193a01898
NIST National Vulnerability Database
git.kernel.org/stable/c/cc14ea21c4e658814d737ed4dedde6cd626a15ad
NIST National Vulnerability Database
git.kernel.org/stable/c/4b97e99b87a773d52699521d40864f3ec888e9a6
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 9h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 9h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-40125 is "blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.23% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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