CVE-2026-93251

/// Technical description

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

ACPI: bus: Introduce acpi_bus_get_primary_device()

The function used for obtaining the first "physical" device for which

the given ACPI one is the ACPI companion, acpi_get_first_physical_node(),

may return a stale device pointer (mostly in theory) because

acpi_unbind_one() may run as a whole after dropping the ACPI device's

physical_node_lock in acpi_get_first_physical_node() and before it

returns. The last reference to the "physical" device may be dropped

then before the pointer to it is returned to the caller.

If that happens and the acpi_get_first_physical_node() caller invokes

get_device() on the pointer obtained from it, which is done by the

majority of its callers, a use-after-free will occur.

To prepare for addressing this problem, introduce a new function for

getting the first "physical" device associated with the given ACPI one

(the "primary physical device") that will also reference count the

device in q

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References