CVE-2026-74547
Received Received - Intake

Busy-loop and I2C Flooding in ADT7470 hwmon Driver

Publication date: 2026-08-15

Last updated on: 2026-08-15

Assigner: kernel.org

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.

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Meta Information

Published
2026-08-15
Last Modified
2026-08-15
Generated
2026-08-15
AI Q&A
2026-08-15
EPSS Evaluated
N/A
NVD
CVE-2026-74547
EUVD
EUVD-2026-59740

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel to 500 (inc)

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Exploitability

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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flaw in the hwmon subsystem for the ADT7470 sensor. When userspace sets the auto_update_interval to 0, the background thread enters a busy-loop if num_temp_sensors is also 0, causing high CPU usage and flooding the I2C bus with continuous transactions.

Detection Guidance

This vulnerability is specific to the Linux kernel's hwmon subsystem (adt7470 driver) and may not have direct network detection methods. Check for high CPU usage by the adt7470 kthread or excessive I2C bus activity using system monitoring tools like top, htop, or i2c-tools. Look for processes named adt7470 or kernel threads related to hwmon.

Impact Analysis

This vulnerability can cause system performance degradation due to high CPU usage and may disrupt I2C bus communication, potentially affecting other hardware components relying on the I2C bus.

Mitigation Strategies

Update your Linux kernel to a version that includes the fix for CVE-2026-74547. Avoid setting 'auto_update_interval' to 0 in sysfs for the adt7470 driver. Monitor system performance and I2C bus activity for signs of abnormal behavior.

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