CVE-2026-97582: hwmon: (gpio-fan) Fix use-after-free in alarm work

CVE-2026-97582: hwmon: (gpio-fan) Fix use-after-free in alarm work

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (gpio-fan) Fix use-after-free in alarm work

fan_alarm_irq_handler() queues fan_data->alarm_work, but nothing
cancels it.  fan_alarm_notify() dereferences fan_data and its hwmon
device.  On unbind, devres frees the interrupt, which only waits for
the handler itself, and then releases the hwmon device and fan_data,
so a pending fan_alarm_notify() can run after those frees.

Replace INIT_WORK() with devm_work_autocancel(), registered before
devm_request_irq().  The devres cleanup then frees the interrupt
first, so no new work can be queued, and cancels the work while
fan_data and the hwmon device are still alive.

This issue was found by an in-house static analysis tool.

The Linux kernel CVE team has assigned CVE-2026-97582 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 2.6.37 with commit d6fe1360f42e86262153927986dea6502daff703 and fixed in 6.12.111 with commit 9b12bd724db9db318e3a68be17693583dc29a066
	Issue introduced in 2.6.37 with commit d6fe1360f42e86262153927986dea6502daff703 and fixed in 6.18.53 with commit 30755d3a5782cd704c8921cac8ee66dffe4383ea
	Issue introduced in 2.6.37 with commit d6fe1360f42e86262153927986dea6502daff703 and fixed in 7.2.7 with commit c6ab7f855891877a16d2e2ddf0cd0305fd098a85
	Issue introduced in 2.6.37 with commit d6fe1360f42e86262153927986dea6502daff703 and fixed in 7.3-rc3 with commit a2471ed17b0e6ff7bfb6b2ea8e6e5b04c309d293

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-97582
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/hwmon/gpio-fan.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/9b12bd724db9db318e3a68be17693583dc29a066
	https://git.kernel.org/stable/c/30755d3a5782cd704c8921cac8ee66dffe4383ea
	https://git.kernel.org/stable/c/c6ab7f855891877a16d2e2ddf0cd0305fd098a85
	https://git.kernel.org/stable/c/a2471ed17b0e6ff7bfb6b2ea8e6e5b04c309d293