# CVE-2026-46017: mm: fix deferred split queue races during migration

> A race condition in the Linux kernel memory management subsystem can cause a kernel warning and potential denial of service during page migration.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/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:** 27 May 2026
- **Updated:** 14 Jun 2026
- **Also known as:** AZL-88425, BELL-CVE-2026-46017, DEBIAN-CVE-2026-46017, GHSA-88w3-x23r-c432, ROOT-OS-DEBIAN-11-CVE-2026-46017, ROOT-OS-DEBIAN-12-CVE-2026-46017, ROOT-OS-DEBIAN-13-CVE-2026-46017, UBUNTU-CVE-2026-46017

## What is CVE-2026-46017?

CVE-2026-46017 is a medium-severity vulnerability in Linux kernel, published on 27 May 2026. 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:

mm: fix deferred split queue races during migration

migrate_folio_move() records the deferred split queue state from src and
replays it on dst.  Replaying it after remove_migration_ptes(src, dst, 0)
makes dst visible before it is requeued, so a concurrent rmap-removal path
can mark dst partially mapped and trip the WARN in deferred_split_folio().

Move the requeue before remove_migration_ptes() so dst is back on the
deferred split queue before it becomes visible again.

Because migration still holds dst locked at that point, teach
deferred_split_scan() to requeue a folio when folio_trylock() fails. 
Otherwise a fully mapped underused folio can be dequeued by the shrinker
and silently lost from split_queue.

[ziy@nvidia.com: move the comment]

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-46017?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46017?

Apply the vendor's patch.

## Is CVE-2026-46017 being exploited?

There is no known exploitation of CVE-2026-46017 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-2026-46017 and fix it if it is affected.

What it is: CVE-2026-46017 is a medium-severity vulnerability in Linux kernel, published on 27 May 2026. 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-2026-46017 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-2026-46017/ (Markdown: https://insights.sbomify.com/CVE-2026-46017/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46017
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46017
- OSV: https://osv.dev/vulnerability/CVE-2026-46017

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46017/
Summaries are generated and may contain mistakes; the official description above is the record.