CVE-2026-64373: Linux Kernel

Medium severity, CVSS 4.7. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: cpufreq: Fix hotplug-suspend race during reboot During system reboot, cpufreq_suspend() is called via the kernel_restart() -> device_shutdown() path. Unlike the normal system suspend path, the reboot path does not call freeze_processes(), so userspace processes and kernel threads remain active. This allows CPU hotplug operations to run concurrently with cpufreq_suspend(). The original code has no synchronization with CPU hotplug, leading to a race condition where governor_data can be freed by the hotplug path while cpufreq_suspend() is still accessing it, resulting in a null pointer dereference: Unable to handle kernel NULL pointer dereference Call Trace: do_kernel_fault+0x28/0x3c cpufreq_suspend+0xdc/0x160 device_shutdown+0x18/0x200 kernel_restart+0x40/0x80 arm64_sys_reboot+0x1b0/0x200 Fix this by adding cpus_read_lock()/cpus_read_unlock() to cpufreq_suspend() to block CPU hotplug operations while suspend is in progress. [ rjw: Changelog edits ]

Affected products

• Linux Linux Kernel: from 4.4.198, before 4.5 (fixed in 4.5); from 4.9.198, before 4.10 (fixed in 4.10); from 4.14.151, before 4.15 (fixed in 4.15); from 4.19.81, before 4.20 (fixed in 4.20); from 5.3.8, before 5.4 (fixed in 5.4); from 5.4.1, before 5.10.261 (fixed in 5.10.261); …

Published 2026-07-25. Last modified 2026-09-08.