# CVE-2024-57881: mm/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy()

> A null pointer dereference in the Linux kernel memory allocator can cause a system crash when freeing specific high-memory pages under sparse memory configurations.

- **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:** 11 Jan 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-57881, DEBIAN-CVE-2024-57881, GHSA-7x5p-5275-mmvg, UBUNTU-CVE-2024-57881

## What is CVE-2024-57881?

CVE-2024-57881 is a medium-severity vulnerability in Linux kernel, published on 11 Jan 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/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy()

In split_large_buddy(), we might call pfn_to_page() on a PFN that might
not exist.  In corner cases, such as when freeing the highest pageblock in
the last memory section, this could result with CONFIG_SPARSEMEM &&
!CONFIG_SPARSEMEM_EXTREME in __pfn_to_section() returning NULL and and
__section_mem_map_addr() dereferencing that NULL pointer.

Let's fix it, and avoid doing a pfn_to_page() call for the first
iteration, where we already have the page.

So far this was found by code inspection, but let's just CC stable as the
fix is easy.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-57881?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-57881?

Apply the vendor's patch.

## Is CVE-2024-57881 being exploited?

There is no known exploitation of CVE-2024-57881 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-2024-57881 and fix it if it is affected.

What it is: CVE-2024-57881 is a medium-severity vulnerability in Linux kernel, published on 11 Jan 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-2024-57881 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-2024-57881/ (Markdown: https://insights.sbomify.com/CVE-2024-57881/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-57881
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-57881
- OSV: https://osv.dev/vulnerability/CVE-2024-57881

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-57881/
Summaries are generated and may contain mistakes; the official description above is the record.