of: dynamic: Synchronize of_changeset_destroy() with the devlink removals

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: of: dynamic: Synchronize of_changeset_destroy() with the devlink removals In the following sequence: 1) of_platform_depopulate() 2) of_overlay_remove() During the step 1, devices are destroyed and devlinks are removed. During the step 2, OF nodes are destroyed but __of_changeset_entry_destroy() can raise warnings related to missing of_node_put(): ERROR: memory leak, expected refcount 1 instead of 2 ... Indeed, during the devlink removals performed at step 1, the removal itself releasing the device (and the attached of_node) is done by a job queued in a workqueue and so, it is done asynchronously with respect to function calls. When the warning is present, of_node_put() will be called but wrongly too late from the workqueue job. In order to be sure that any ongoing devlink removals are done before the of_node destruction, synchronize the of_changeset_destroy() with the devlink removals.

References

• https://git.kernel.org/stable/c/3127b2ee50c424a96eb3559fbb7b43cf0b111c7a
• https://git.kernel.org/stable/c/3ee2424107546d882e1ddd75333ca9c32879908c
• https://git.kernel.org/stable/c/7b6df050c45a1ea158fd50bc32a8e1447dd1e951
• https://git.kernel.org/stable/c/801c8b8ec5bfb3519566dff16a5ecd48302fca82
• https://git.kernel.org/stable/c/ae6d76e4f06c37a623e357e79d49b17411db6f5c
• https://git.kernel.org/stable/c/8917e7385346bd6584890ed362985c219fe6ae84