CVE-2026-46292

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

pmdomain: core: Fix detach procedure for virtual devices in genpd

If a device is attached to a PM domain through genpd_dev_pm_attach_by_id(), genpd calls pm_runtime_enable() for the corresponding virtual device that it registers. While this avoids boilerplate code in drivers, there is no corresponding call to pm_runtime_disable() in genpd_dev_pm_detach().

This means these virtual devices are typically detached from its genpd, while runtime PM remains enabled for them, which is not how things are designed to work. In worst cases it may lead to critical errors, like a NULL pointer dereference bug in genpd_runtime_suspend(), which was recently reported. For another case, we may end up keeping an unnecessary vote for a performance state for the device.

To fix these problems, lets add this missing call to pm_runtime_disable() in genpd_dev_pm_detach().

Weakness

The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.
• Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems.
• When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users.
• Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/469.html

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/52e485ed0dcb5496864003ba9ffcef7d5b613f83
• https://git.kernel.org/stable/c/707cb5df3eab32ddc52979418f7ace62941e6381
• https://git.kernel.org/stable/c/8d44391a7f29e4601e8243f13498d0219bab2576
• https://git.kernel.org/stable/c/98b8104978474d381256a2b2fb0e7ca8e05a7bfa
• https://git.kernel.org/stable/c/e8f8dad44f024a5c99e54a48ad5c943fa8e54319