Service interruption via incorrect clock-divider calculation
Published Oct 9, 2025 · Updated Oct 9, 2025
Divide-by-zero in Linux kernel 6.15 through 6.16.8 and 6.17 release candidates causes a service interrupt during clock-rate readback. The sunxi-ng ccu_mp.c .recalc_rate path uses the raw P-divider field without adding its configured offset before dividing the parent rate. The fault requires the P-divider hardware register to contain zero, a firmware or hardware condition that Ubuntu reports attackers cannot trigger or influence.
Summary
What happened
Divide-by-zero in Linux kernel 6.15 through 6.16.8 and 6.17 release candidates causes a service interrupt during clock-rate readback. The sunxi-ng ccu_mp.c .recalc_rate path uses the raw P-divider field without adding its configured offset before dividing the parent rate. The fault requires the P-divider hardware register to contain zero, a firmware or hardware condition that Ubuntu reports attackers cannot trigger or influence.
The record
- CVE
- CVE-2025-39954
- Published
- Oct 9, 2025
- Updated
- Oct 9, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-369
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 9, 2025CVE publishedPublication date reported by the CVE source.
- Oct 9, 2025Record 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=45717804b75eda8a76eacc04509ca4d68dd2caaf <25fbbaf515acd13399589bd5ee6de5f35740cef2
- Affected versionversion=45717804b75eda8a76eacc04509ca4d68dd2caaf <40108f69c372af3aea73e7829d6849a44638d662
- Affected versionversion=6.15
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What is affected?
Published CVSS scores
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Attacks
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Technologies
Your stack
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Your stack
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