Bug 2517038 (CVE-2026-74547) - CVE-2026-74547 kernel: hwmon: (adt7470) Fix busy-loop and I2C flooding in update thread
Summary: CVE-2026-74547 kernel: hwmon: (adt7470) Fix busy-loop and I2C flooding in upd...
Keywords:
Status: NEW
Alias: CVE-2026-74547
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 12:46 UTC by OSIDB Bzimport
Modified: 2026-08-19 19:07 UTC (History)
2 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-08-15 12:46:13 UTC
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.

Comment 1 Mauro Matteo Cascella 2026-08-19 19:01:50 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081549-CVE-2026-74547-6a6e@gregkh/T


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