Service interruption via overflowing fan-speed divisor
Published May 1, 2025 · Updated May 11, 2026
Divide-by-zero in affected Linux kernel releases since 4.20 allows local users to interrupt service by setting an excessive AMD GPU fan speed. The smu7_fan_ctrl_set_fan_speed_rpm function multiplies the untrusted speed by eight in a 32-bit divisor, allowing wraparound to zero before calculating the tachometer period. The path requires local low-privileged access and compatible AMD GPU hardware; no confidentiality or integrity impact is reported.
Summary
What happened
Divide-by-zero in affected Linux kernel releases since 4.20 allows local users to interrupt service by setting an excessive AMD GPU fan speed. The smu7_fan_ctrl_set_fan_speed_rpm function multiplies the untrusted speed by eight in a 32-bit divisor, allowing wraparound to zero before calculating the tachometer period. The path requires local low-privileged access and compatible AMD GPU hardware; no confidentiality or integrity impact is reported.
The record
- CVE
- CVE-2025-37768
- Published
- May 1, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-369, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 1, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 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?
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- Affected versionversion=4.20
- Affected versionversion=c52dcf49195d06319189c7f1dd8b62bfca545197 <3cdd02cb70682d7d205ca6dc02a4d1eb76758d24
- Affected versionversion=c52dcf49195d06319189c7f1dd8b62bfca545197 <5fc4fb54f6f064c25bfbbfd443aa861d3422dd4c
- Affected versionversion=c52dcf49195d06319189c7f1dd8b62bfca545197 <7c246a05df51c52fe0852ce56ba10c41e6ed1f39
- Affected versionversion=c52dcf49195d06319189c7f1dd8b62bfca545197 <8e9c4f8d197d5709c75effa5d58e80b4fa01981a
- Affected versionversion=c52dcf49195d06319189c7f1dd8b62bfca545197 <9e4f1e21fe7b93a8ef57db433071266c2590e260
- Affected versionversion=c52dcf49195d06319189c7f1dd8b62bfca545197 <b0742a709be7979c7a480772046a1f36d09dab00
- Affected versionversion=c52dcf49195d06319189c7f1dd8b62bfca545197 <be0fffc4152aac4f0291ed2d793f3cfee788449d
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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Weakness, pattern, technique
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Technologies
Your stack
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Your stack
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