Executive brief
A vulnerability was identified in the Linux kernel's power management component that could cause system instability. When certain virtual devices are disconnected from their power domains, the system fails to properly shut down their power management tasks. This can lead to system crashes (specifically a NULL pointer dereference) or inefficient power usage, potentially impacting the reliability of servers or embedded devices.
Technical details
A vulnerability exists in the Linux kernel's pmdomain core where virtual devices attached via genpd_dev_pm_attach_by_id() are not properly cleaned up during detachment. While genpd calls pm_runtime_enable() during attachment, it lacks a corresponding pm_runtime_disable() call in genpd_dev_pm_detach(). This leaves runtime PM enabled for detached virtual devices, which can trigger a NULL pointer dereference in genpd_runtime_suspend() or result in stale performance state votes. The issue is resolved by adding the missing pm_runtime_disable() call to the detachment procedure.
Affected products
- Linux Linux Kernel Versions prior to 6.9 (specifically affecting genpd)
Timeline
- 2026-04-17: other: Initial patch authored
- 2026-06-08: disclosed: CVE published
References
- https://git.kernel.org/stable/c/26735dfdd8930d9ef1fa92e590a9bf77726efdf6
- https://git.kernel.org/stable/c/361518a26e4434e879db6ff43bf364795dcbfbff
- https://git.kernel.org/stable/c/51a7dd9cbae9210335ce398642ecaaa52c939eb5
- https://git.kernel.org/stable/c/707cb5df3eab32ddc52979418f7ace62941e6381
- https://git.kernel.org/stable/c/8d44391a7f29e4601e8243f13498d0219bab2576