pmdomain: mediatek: fix use-after-free in scpsys_get_bus_protection_legacy()

CVE-2026-46308

What is CVE-2026-46308?

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

pmdomain: mediatek: fix use-after-free in scpsys_get_bus_protection_legacy()

In scpsys_get_bus_protection_legacy(), of_find_node_with_property() returns a device node with its reference count incremented. The function then calls of_node_put(node) before checking whether syscon_regmap_lookup_by_phandle() returns an error. If an error occurs, dev_err_probe() dereferences the node pointer to print diagnostic information, but the node memory may have already been freed due to the earlier of_node_put(), leading to a use-after-free vulnerability.

Fix this by moving the of_node_put() call after the error check, ensuring the node is still valid when accessed in the error path.

References