CVE-2025-39954: clk: sunxi-ng: mp: Fix dual-divider clock rate readback

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-09 · updated 2026-10-19
Weakness: CWE-369

Description

In the Linux kernel, the following vulnerability has been resolved: clk: sunxi-ng: mp: Fix dual-divider clock rate readback When dual-divider clock support was introduced, the P divider offset was left out of the .recalc_rate readback function. This causes the clock rate to become bogus or even zero (possibly due to the P divider being 1, leading to a divide-by-zero). Fix this by incorporating the P divider offset into the calculation.

Affected products

Linux kernel: from 6.15 before 6.16.9; 6.17-rc1, 6.17-rc2, 6.17-rc3, 6.17-rc4, 6.17-rc5, 6.17-rc6 — fixed in 6.16.9

How to fix

Upgrade to a fixed version: Linux kernel 6.16.9. Check the vendor advisory for mitigations.

References

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