CVE-2025-38584

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> padata: Fix pd UAF once and for all<br /> <br /> There is a race condition/UAF in padata_reorder that goes back<br /> to the initial commit. A reference count is taken at the start<br /> of the process in padata_do_parallel, and released at the end in<br /> padata_serial_worker.<br /> <br /> This reference count is (and only is) required for padata_replace<br /> to function correctly. If padata_replace is never called then<br /> there is no issue.<br /> <br /> In the function padata_reorder which serves as the core of padata,<br /> as soon as padata is added to queue-&gt;serial.list, and the associated<br /> spin lock released, that padata may be processed and the reference<br /> count on pd would go away.<br /> <br /> Fix this by getting the next padata before the squeue-&gt;serial lock<br /> is released.<br /> <br /> In order to make this possible, simplify padata_reorder by only<br /> calling it once the next padata arrives.