CVE-2026-74546: hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-15 · updated 2026-08-19

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read If the fan data becomes 0 between the FAN_DATA_VALID() check and the FAN_PERIOD_TO_RPM() conversion, it will result in a divide-by-zero crash due to a race with a concurrent update of the cached fan value. Fix a TOCTOU issue by reading fan data once.

Affected products

Linux kernel: 5.15 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/009240d057e26831cc925feaba4c490209c1d0ba
https://git.kernel.org/stable/c/1b46fe9dc8f8de59310f37e6c5e5c0e05ded46c3
https://git.kernel.org/stable/c/689a2ea75434131d0af58aeb7d51fde40e858b4d
https://git.kernel.org/stable/c/76963b04b2d1c648d69949d8dd521e1ff7f40b51
https://git.kernel.org/stable/c/832069bec79cf6f903441c5769d3cdba95d0af33
https://git.kernel.org/stable/c/96ad57d31763559d376416cdf3bf5ae79bbbebec
https://git.kernel.org/stable/c/d328175045176f85c15c369bd21dc551351e7935

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