Kernel crash via wrapped ftrace statistics denominator
Published Apr 1, 2025 · Updated May 23, 2026
Divide-by-zero in Linux kernel ftrace statistics allows local users to crash the kernel by reading function-profile output. function_stat_show() multiplies the sample count into a fixed-width standard-deviation denominator without first rejecting values whose arithmetic wraparound produces zero. Reaching the calculation requires local access to configured ftrace function profiling and its tracefs statistics output, and the reported consequence is limited to availability.
Summary
What happened
Divide-by-zero in Linux kernel ftrace statistics allows local users to crash the kernel by reading function-profile output. function_stat_show() multiplies the sample count into a fixed-width standard-deviation denominator without first rejecting values whose arithmetic wraparound produces zero. Reaching the calculation requires local access to configured ftrace function profiling and its tracefs statistics output, and the reported consequence is limited to availability.
The record
- CVE
- CVE-2025-21898
- Published
- Apr 1, 2025
- Updated
- May 23, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-369, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 1, 2025CVE publishedPublication date reported by the CVE source.
- May 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=010a7e846d4beaf34384c40ff18d5de10106d9b4
- Affected versionversion=015f0fd0fcc338513f80044add27fa46cf71d217
- Affected versionversion=1a2985af2a20b816a5cc41a2ddc1c4109ef6b9c6
- Affected versionversion=3.16.83 <3.17
- Affected versionversion=4.14.163 <4.15
- Affected versionversion=4.19.94 <4.20
- Affected versionversion=4.4.209 <4.5
- Affected versionversion=4.9.209 <4.10
- Affected versionversion=5.4.9 <5.4.291
- Affected versionversion=5.5
- Affected versionversion=7650b4b1df091815bbbbb837d308dd4154684f8a
- Affected versionversion=c59e74104cfd7df3ca0b5f59f1baee9c8c28b9ef
- Affected versionversion=e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d <3d738b53ed6cddb68e68c9874520a4bf846163b5
- Affected versionversion=e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d <746cc474a95473591853927b3a9792a2d671155b
- Affected versionversion=e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d <992775227843c9376773784b8b362add44592ad7
- Affected versionversion=e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d <9cdac46fa7e854e587eb5f393fe491b6d7a9bdf6
- Affected versionversion=e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d <a1a7eb89ca0b89dc1c326eeee2596f263291aca3
- Affected versionversion=e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d <ca381f60a3bb7cfaa618d73ca411610bd7fc3149
- Affected versionversion=e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d <f58a3f8e284d0bdf94164a8e61cd4e70d337a1a3
- Affected versionversion=f0629ee3922f10112584b1898491fecc74d98b3b <5b3d32f607f0478b414b16516cf27f9170cf66c8
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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