Unknown

CVE-2025-40134 — dm: fix NULL pointer dereference in __dm_suspend()

In the Linux kernel, the following vulnerability has been resolved: dm: fix NULL pointer dereference in __dm_suspend() There is a race condition between dm device suspend and table load that can lead to null pointer dereference. The issue occurs when suspend is invoked before table load completes: BUG: kernel NULL pointer dereference, address: 0000000000000054 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 6798 Comm: dmsetup Not tainted 6.6.0-g7e52f5f0ca9b #62 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:blk_mq_wait_quiesce_done+0x0/0x50 Call Trace: <TASK> blk_mq_quiesce_queue+0x2c/0x50 dm_stop_queue+0xd/0x20 __dm_suspend+0x130/0x330 dm_suspend+0x11a/0x180 dev_suspend+0x27e/0x560 ctl_ioctl+0x4cf/0x850 dm_ctl_ioctl+0xd/0x20 vfs_ioctl+0x1d/0x50 __se_sys_ioctl+0x9b/0xc0 __x64_sys_ioctl+0x19/0x30 x64_sys_call+0x2c4a/0x4620 do_syscall_64+0x9e/0x1b0 The issue can be triggered as below: T1 T2 dm_suspend table_load __dm_suspend dm_setup_md_queue dm_mq_init_request_queue blk_mq_init_allocated_queue => q->mq_ops = set->ops; (1) dm_stop_queue / dm_wait_for_completion => q->tag_set NULL pointer! (2) => q->tag_set = set; (3) Fix this by checking if a valid table (map) exists before performing request-based suspend and waiting for target I/O. When map is NULL, skip these table-dependent suspend steps. Even when map is NULL, no I/O can reach any target because there is no table loaded; I/O submitted in this state will fail early in the DM layer. Skipping the table-dependent suspend logic in this case is safe and avoids NULL pointer dereferences.

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	≥ c4576aed8d85d808cd6443bda58393d525207d01 and < 9dc43ea6a20ff83fe9a5fe4be47ae0fbf2409b98≥ c4576aed8d85d808cd6443bda58393d525207d01 and < 30f95b7eda5966b81cb221bd569c0f095a068cf6≥ c4576aed8d85d808cd6443bda58393d525207d01 and < a0e54bd8d7ea79127fe9920df3ae36f85e79ac7c≥ c4576aed8d85d808cd6443bda58393d525207d01 and < a802901b75e13cc306f1b7ab0f062135c8034e9e≥ c4576aed8d85d808cd6443bda58393d525207d01 and < 846cafc4725ca727d94f9c4b5f789c1a7c8fb6fe≥ c4576aed8d85d808cd6443bda58393d525207d01 and < 19ca4528666990be376ac3eb6fe667b03db5324d≥ c4576aed8d85d808cd6443bda58393d525207d01 and < 331c2dd8ca8bad1a3ac10cce847ffb76158eece4≥ c4576aed8d85d808cd6443bda58393d525207d01 and < 8d33a030c566e1f105cd5bf27f37940b6367f3be and 1 more version 5.0	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/19ca4528666990be376ac3eb6fe667b03db5324d
NIST National Vulnerability Database
git.kernel.org/stable/c/30f95b7eda5966b81cb221bd569c0f095a068cf6
NIST National Vulnerability Database
git.kernel.org/stable/c/a802901b75e13cc306f1b7ab0f062135c8034e9e
NIST National Vulnerability Database
git.kernel.org/stable/c/331c2dd8ca8bad1a3ac10cce847ffb76158eece4
NIST National Vulnerability Database
git.kernel.org/stable/c/8d33a030c566e1f105cd5bf27f37940b6367f3be
NIST National Vulnerability Database
git.kernel.org/stable/c/846cafc4725ca727d94f9c4b5f789c1a7c8fb6fe
NIST National Vulnerability Database
git.kernel.org/stable/c/9dc43ea6a20ff83fe9a5fe4be47ae0fbf2409b98
NIST National Vulnerability Database
git.kernel.org/stable/c/a0e54bd8d7ea79127fe9920df3ae36f85e79ac7c
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 8h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 8h
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-2025-40134 is "dm: fix NULL pointer dereference in __dm_suspend()", 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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