CVE-2025-21655

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period<br /> <br /> io_eventfd_do_signal() is invoked from an RCU callback, but when<br /> dropping the reference to the io_ev_fd, it calls io_eventfd_free()<br /> directly if the refcount drops to zero. This isn&amp;#39;t correct, as any<br /> potential freeing of the io_ev_fd should be deferred another RCU grace<br /> period.<br /> <br /> Just call io_eventfd_put() rather than open-code the dec-and-test and<br /> free, which will correctly defer it another RCU grace period.