# CVE-2023-52598: s390/ptrace: handle setting of fpc register correctly

> A flaw in the Linux kernel s390 ptrace implementation allows register corruption, potentially enabling privilege escalation or code execution.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 6 Mar 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-52598, DEBIAN-CVE-2023-52598, GHSA-c4rp-h96r-7xm9, UBUNTU-CVE-2023-52598

## What is CVE-2023-52598?

CVE-2023-52598 is a high-severity memory corruption vulnerability in Linux kernel, published on 6 Mar 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/ptrace: handle setting of fpc register correctly

If the content of the floating point control (fpc) register of a traced
process is modified with the ptrace interface the new value is tested for
validity by temporarily loading it into the fpc register.

This may lead to corruption of the fpc register of the tracing process:
if an interrupt happens while the value is temporarily loaded into the
fpc register, and within interrupt context floating point or vector
registers are used, the current fp/vx registers are saved with
save_fpu_regs() assuming they belong to user space and will be loaded into
fp/vx registers when returning to user space.

test_fp_ctl() restores the original user space fpc register value, however
it will be discarded, when returning to user space.

In result the tracer will incorrectly continue to run with the value that
was supposed to be used for the traced process.

Fix this by saving fpu register contents with save_fpu_regs() before using
test_fp_ctl().

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2023-52598?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52598?

Apply the vendor's patch.

## Is CVE-2023-52598 being exploited?

There is no known exploitation of CVE-2023-52598 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-2023-52598 and fix it if it is affected.

What it is: CVE-2023-52598 is a high-severity memory corruption vulnerability in Linux kernel, published on 6 Mar 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-2023-52598 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-2023-52598/ (Markdown: https://insights.sbomify.com/CVE-2023-52598/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52598
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52598
- OSV: https://osv.dev/vulnerability/CVE-2023-52598

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52598/
Summaries are generated and may contain mistakes; the official description above is the record.