CVE-2026-74547: hwmon: (adt7470) Fix busy-loop and I2C flooding in update thread

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 busy-loop and I2C flooding in update thread When userspace configures 'auto_update_interval' to 0 via sysfs, the background kthread executes schedule_timeout_interruptible(0), which returns immediately. If 'num_temp_sensors' is concurrently or previously set to 0, the msleep_interruptible() delay inside adt7470_read_temperatures() also becomes 0. This combination forces the background thread into a tight, unbounded busy-loop, hogging the CPU and flooding the I2C bus with a continuous stream of transactions. Fix this vulnerability by raising the lower limit of the clamp_val in auto_update_interval_store() from 0 to 500 milliseconds. This guarantees a reasonable minimum sleep window between sensor updates, protecting the system from intentional or accidental I2C bus denial of service.

Affected products

Linux kernel: 2.6.29 — fixed in 7.2

How to fix

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

References

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