CVE-2026-97946

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

x86/amd node: Fix PCI device reference counting in amd smn init()

The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete.

Use the free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The pci get class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL.