CVE-2026-74552

What the bug is

Userspace can read sysfs attributes before driver registration is complete, immediately after devm_hwmon_device_register_with_info() has been called. At that time, data->hwmon_dev is not yet initialized. This can trigger a NULL pointer access since lm90_update_device() and with it lm90_update_alarms_locked() will be called. This call schedules report_work and lm90_report_alarms(), which passes the still-NULL data->hwmon_dev to hwmon_notify_event() and triggers a NULL pointer dereference. Fix the problem by only scheduling the report and alert workers data->hwmon_dev is set.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/hwmon/lm90.c

What this is

LM90 HARDWARE MONITOR DRIVERMAINTAINERS section matched on drivers/hwmon/lm90.c · linux-hwmon@vger.kernel.org · Maintained

Kernel module

lm90

Check it on the machine

grep -wE 'CONFIG_HWMON|CONFIG_SENSORS_LM90' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w lm90

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp
• trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_HWMON, CONFIG_SENSORS_LM90

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-08-15 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 6.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/hwmon

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.0	6.1.183	31ce62d36d85
6.0	6.6.151	4eed33c7db5c
6.0	6.12.103	70d9a71aa407
6.0	6.18.44	075fce376cf8
6.0	7.1.8	f0b791a00651
6.0	7.2	aa9429edf9fc

Debian advisories