CVE-2026-74552

Name	CVE-2026-74552
Description	In the Linux kernel, the following vulnerability has been resolved: hwmon: (lm90) Only report alarms if driver is ready 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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4777-1, DLA-4788-1, DSA-6466-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bookworm	6.1.176-1	vulnerable
	bookworm (security)	6.1.187-1	fixed
	trixie (security), trixie	6.12.107-1	fixed
	forky	7.2.6-1	fixed
	sid	7.2.8-1	fixed
linux-6.12 (PTS)	bookworm (security)	6.12.107-1~deb12u1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin
linux	source	bullseye	(not affected)
linux	source	bookworm	6.1.187-1	DLA-4777-1
linux	source	trixie	6.12.105-1	DSA-6466-1
linux	source	(unstable)	7.1.8-1
linux-6.12	source	bookworm	6.12.107-1~deb12u1	DLA-4788-1

[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/aa9429edf9fc0e90d6f4da19ea4b5495a54ab117 (7.2-rc6)