What’s Vulnerable › Vulnerabilities
CVE-2025-21898: ftrace: Avoid potential division by zero in function_stat_show()
- Severity: medium (CVSS 5.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-04-01 · updated 2026-06-17
- Weakness: CWE-369
Description
In the Linux kernel, the following vulnerability has been resolved: ftrace: Avoid potential division by zero in function_stat_show() Check whether denominator expression x * (x - 1) * 1000 mod {2^32, 2^64} produce zero and skip stddev computation in that case. For now don't care about rec->counter * rec->counter overflow because rec->time * rec->time overflow will likely happen earlier.
Affected products
- Linux kernel: from 3.16.83 before 3.17; from 4.4.206 before 4.5; from 4.9.209 before 4.10; from 4.14.163 before 4.15; from 4.19.94 before 4.20; from 5.4.9 before 5.4.291 — fixed in 3.17, 4.10, 4.15, 4.20, 4.5, 5.10.235
How to fix
Upgrade to a fixed version: Linux kernel 3.17, 4.10, 4.15, 4.20. Check the vendor advisory for mitigations.
References
- https://git.kernel.org/stable/c/3d738b53ed6cddb68e68c9874520a4bf846163b5
- https://git.kernel.org/stable/c/5b3d32f607f0478b414b16516cf27f9170cf66c8
- https://git.kernel.org/stable/c/746cc474a95473591853927b3a9792a2d671155b
- https://git.kernel.org/stable/c/992775227843c9376773784b8b362add44592ad7
- https://git.kernel.org/stable/c/9cdac46fa7e854e587eb5f393fe491b6d7a9bdf6
- https://git.kernel.org/stable/c/a1a7eb89ca0b89dc1c326eeee2596f263291aca3
- https://git.kernel.org/stable/c/ca381f60a3bb7cfaa618d73ca411610bd7fc3149
- https://git.kernel.org/stable/c/f58a3f8e284d0bdf94164a8e61cd4e70d337a1a3
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
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