In the Linux kernel, the following vulnerability has been resolved:
riscv: Prevent a bad reference count on CPU nodes
When populating cache leaves we previously fetched the CPU device node at the very beginning. But when ACPI is enabled we go through a specific branch which returns early and does not call 'ofnodeput' for the node that was acquired.
Since we are not using a CPU device node for the ACPI code anyways, we can simply move the initialization of it just passed the ACPI block, and we are guaranteed to have an 'ofnodeput' call for the acquired node. This prevents a bad reference count of the CPU device node.
Moreover, the previous function did not check for errors when acquiring the device node, so a return -ENOENT has been added for that case.