# CVE-2023-1583: Null dereference in Linux kernel

> An unprivileged user can trigger a system crash via a NULL pointer dereference in the Linux kernel's io_uring component.

- **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:** 24 Mar 2023
- **Updated:** 20 Feb 2025
- **Also known as:** DEBIAN-CVE-2023-1583, GHSA-p732-x236-jpq6, UBUNTU-CVE-2023-1583

## What is CVE-2023-1583?

CVE-2023-1583 is a medium-severity vulnerability in Linux kernel, published on 24 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A NULL pointer dereference was found in io_file_bitmap_get in io_uring/filetable.c in the io_uring sub-component in the Linux Kernel. When fixed files are unregistered, some context information (file_alloc_{start,end} and alloc_hint) is not cleared. A subsequent request that has auto index selection enabled via IORING_FILE_INDEX_ALLOC can cause a NULL pointer dereference. An unprivileged user can use the flaw to cause a system crash.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-1583?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-1583?

Apply the vendor's patch.

## Is CVE-2023-1583 being exploited?

There is no known exploitation of CVE-2023-1583 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-2023-1583 and fix it if it is affected.

What it is: CVE-2023-1583 is a medium-severity vulnerability in Linux kernel, published on 24 Mar 2023. 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-2023-1583 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-2023-1583/ (Markdown: https://insights.sbomify.com/CVE-2023-1583/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-1583
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-1583
- OSV: https://osv.dev/vulnerability/CVE-2023-1583

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-1583/
Summaries are generated and may contain mistakes; the official description above is the record.