CVE-2026-64292

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> iommufd: Move vevent memory allocation outside spinlock<br /> <br /> The veventq memory allocation happens inside the spinlock. Given its depth<br /> is decided by the user space, this leaves a vulnerability, where userspace<br /> can allocate large queues to exhaust atomic memory reserves.<br /> <br /> Move the allocation outside the spinlock and use GFP_NOWAIT, which can fail<br /> fast under memory pressure without dipping into the GFP_ATOMIC reserves or<br /> direct-reclaiming from the threaded IRQ handler. On allocation failure,<br /> queue the lost_events_header (so userspace learns of the drop) and return<br /> -ENOMEM so the caller learns of the kernel-side memory pressure.<br /> <br /> This is intentionally distinct from the queue-overflow path, which also<br /> queues the lost_events_header but returns 0: a full queue is an expected<br /> userspace-pacing condition rather than a kernel error.<br /> <br /> A subsequent change will cap the upper bound of the veventq_depth.