# CVE-2025-68293: mm/huge_memory: fix NULL pointer deference when splitting folio

> A NULL pointer dereference in the Linux kernel's huge memory management allows local attackers to cause a system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-68293, DEBIAN-CVE-2025-68293, GHSA-r3mj-3wvr-4c72, ROOT-OS-DEBIAN-13-CVE-2025-68293, UBUNTU-CVE-2025-68293

## What is CVE-2025-68293?

CVE-2025-68293 is a vulnerability in Linux, published on 16 Dec 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:

mm/huge_memory: fix NULL pointer deference when splitting folio

Commit c010d47f107f ("mm: thp: split huge page to any lower order pages")
introduced an early check on the folio's order via mapping->flags before
proceeding with the split work.

This check introduced a bug: for shmem folios in the swap cache and
truncated folios, the mapping pointer can be NULL.  Accessing
mapping->flags in this state leads directly to a NULL pointer dereference.

This commit fixes the issue by moving the check for mapping != NULL before
any attempt to access mapping->flags.

## Which versions are affected by CVE-2025-68293?


## How do I fix CVE-2025-68293?

Apply the vendor's patch.

## Is CVE-2025-68293 being exploited?

There is no known exploitation of CVE-2025-68293 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68293 and fix it if it is affected.

What it is: CVE-2025-68293 is a vulnerability in Linux, published on 16 Dec 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-2025-68293 in the wild and no public exploit code.

Affected product: Linux. 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-2025-68293/ (Markdown: https://insights.sbomify.com/CVE-2025-68293/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68293
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68293
- OSV: https://osv.dev/vulnerability/CVE-2025-68293

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68293/
Summaries are generated and may contain mistakes; the official description above is the record.