CVE-2017-18224 — In the Linux kernel before 4

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.

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2018-03-12T03:00:00.000Z
• Last modified: 2024-08-05T21:13:49.057Z

09References

• git.kernel.org — http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3e4c56…
• github.com — https://github.com/torvalds/linux/commit/3e4c56d41eef5595035872a2ec5a483f42e8917…
• www.debian.org — https://www.debian.org/security/2018/dsa-4188
• www.securityfocus.com — http://www.securityfocus.com/bid/103353