# CVE-2024-42235: s390/mm: Add NULL pointer check to crst_table_free() base_crst_free()

> A missing NULL pointer check in the s390 memory management code can cause a kernel crash if page allocation fails under specific test conditions.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 7 Aug 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-47543, BELL-CVE-2024-42235, DEBIAN-CVE-2024-42235, GHSA-rx9p-j44h-69cp, UBUNTU-CVE-2024-42235

## What is CVE-2024-42235?

CVE-2024-42235 is a high-severity vulnerability in Linux kernel, published on 7 Aug 2024. 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:

s390/mm: Add NULL pointer check to crst_table_free() base_crst_free()

crst_table_free() used to work with NULL pointers before the conversion
to ptdescs.  Since crst_table_free() can be called with a NULL pointer
(error handling in crst_table_upgrade() add an explicit check.

Also add the same check to base_crst_free() for consistency reasons.

In real life this should not happen, since order two GFP_KERNEL
allocations will not fail, unless FAIL_PAGE_ALLOC is enabled and used.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-42235?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-42235?

Apply the vendor's patch.

## Is CVE-2024-42235 being exploited?

There is no known exploitation of CVE-2024-42235 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-2024-42235 and fix it if it is affected.

What it is: CVE-2024-42235 is a high-severity vulnerability in Linux kernel, published on 7 Aug 2024. 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-2024-42235 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-2024-42235/ (Markdown: https://insights.sbomify.com/CVE-2024-42235/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-42235
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-42235
- OSV: https://osv.dev/vulnerability/CVE-2024-42235

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-42235/
Summaries are generated and may contain mistakes; the official description above is the record.