CVE-2017-18249

Severity: high (CVSS 7.0 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-03-26 · updated 2026-06-17
Weakness: CWE-362

Description

The add_free_nid function in fs/f2fs/node.c in the Linux kernel before 4.12 does not properly track an allocated nid, which allows local users to cause a denial of service (race condition) or possibly have unspecified other impact via concurrent threads.

Affected products

Debian Linux: 8.0
Linux kernel: before 4.12 — fixed in 4.12

How to fix

Upgrade to a fixed version: Linux kernel 4.12. Check the vendor advisory for mitigations.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=30a61ddf8117c26ac5b295e1233eaa9629a94ca3
http://www.securitytracker.com/id/1041432
https://github.com/torvalds/linux/commit/30a61ddf8117c26ac5b295e1233eaa9629a94ca3
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html
https://usn.ubuntu.com/3932-1/
https://usn.ubuntu.com/3932-2/
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=30a61ddf8117c26ac5b295e1233eaa9629a94ca3
http://www.securitytracker.com/id/1041432
https://github.com/torvalds/linux/commit/30a61ddf8117c26ac5b295e1233eaa9629a94ca3
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html
https://usn.ubuntu.com/3932-1/
https://usn.ubuntu.com/3932-2/

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