Linux Kernel Clock Rate Calculation Flaw in Sunxi-ng MP

CVE-2025-39954

What is CVE-2025-39954?

A vulnerability exists in the Linux kernel's Sunxi-ng MP module, where the P divider offset is not considered during the .recalc_rate function for dual-divider clocks. This oversight can lead to incorrect clock rates, potentially resulting in erroneous data processing or system instability. The calculate function may return incorrect or zero clock rates, particularly when the P divider value is set to 1, risking divide-by-zero errors. This issue has been addressed in a recent patch that incorporates the necessary offset into the calculation, enhancing the reliability and accuracy of clock rate outputs.

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