CVE-2024-35879

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

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

In the following sequence: 1) ofplatformdepopulate() 2) ofoverlayremove()

During the step 1, devices are destroyed and devlinks are removed. During the step 2, OF nodes are destroyed but _ofchangesetentrydestroy() can raise warnings related to missing ofnodeput(): 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 ofnode) 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, ofnode_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 ofnode destruction, synchronize the ofchangeset_destroy() with the devlink removals.