# CVE-2025-38140: dm: limit swapping tables for devices with zone write plugs

> A flaw in the Linux kernel device mapper allows invalid memory access when swapping tables for devices with zone write plugs, potentially causing a crash.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Jul 2025
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-64595, AZL-70642, BELL-CVE-2025-38140, DEBIAN-CVE-2025-38140, GHSA-3g7h-wv72-q2hf, ROOT-OS-DEBIAN-12-CVE-2025-38140, ROOT-OS-DEBIAN-13-CVE-2025-38140, ROOT-OS-UBUNTU-2204-CVE-2025-38140, ROOT-OS-UBUNTU-2404-CVE-2025-38140, UBUNTU-CVE-2025-38140

## What is CVE-2025-38140?

CVE-2025-38140 is a medium-severity vulnerability in Linux kernel, published on 3 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

dm: limit swapping tables for devices with zone write plugs

dm_revalidate_zones() only allowed new or previously unzoned devices to
call blk_revalidate_disk_zones(). If the device was already zoned,
disk->nr_zones would always equal md->nr_zones, so dm_revalidate_zones()
returned without doing any work. This would make the zoned settings for
the device not match the new table. If the device had zone write plug
resources, it could run into errors like bdev_zone_is_seq() reading
invalid memory because disk->conv_zones_bitmap was the wrong size.

If the device doesn't have any zone write plug resources, calling
blk_revalidate_disk_zones() will always correctly update device.  If
blk_revalidate_disk_zones() fails, it can still overwrite or clear the
current disk->nr_zones value. In this case, DM must restore the previous
value of disk->nr_zones, so that the zoned settings will continue to
match the previous value that it fell back to.

If the device already has zone write plug resources,
blk_revalidate_disk_zones() will not correctly update them, if it is
called for arbitrary zoned device changes.  Since there is not much need
for this ability, the easiest solution is to disallow any table reloads
that change the zoned settings, for devices that already have zone plug
resources.  Specifically, if a device already has zone plug resources
allocated, it can only switch to another zoned table that also emulates
zone append.  Also, it cannot change the device size or the zone size. A
device can switch to an error target.

## Which versions are affected by CVE-2025-38140?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38140?

Apply the vendor's patch.

## Is CVE-2025-38140 being exploited?

There is no known exploitation of CVE-2025-38140 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38140 and fix it if it is affected.

What it is: CVE-2025-38140 is a medium-severity vulnerability in Linux kernel, published on 3 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-38140 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-38140/ (Markdown: https://insights.sbomify.com/CVE-2025-38140/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38140
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38140
- OSV: https://osv.dev/vulnerability/CVE-2025-38140

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38140/
Summaries are generated and may contain mistakes; the official description above is the record.