CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's device mapper (dm) functionality, specifically within the `dm_poll_bio()` callback, which can lead to RCU CPU stalls when using io_uring IOPOLL on a dm-stripe target. This issue arises from unbounded polling behavior that can cause performance degradation and system instability. System administrators and developers managing Linux environments that utilize device mapping should prioritize addressing this vulnerability to ensure system reliability and performance.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: dm: limit target bio polling to one shot dm_poll_bio() is the ->poll_bio() callback for a stacked dm device. The caller only knows about the dm queue, so it may decide to do a spinning poll if it thinks a single queue is being polled. Passing those flags unchanged to the mapped clone lets blk_mq_poll() spin on a target queue from inside dm_poll_bio(). With io_uring IOPOLL on a dm-stripe target this can keep a task in dm_poll_bio() -> bio_poll() -> blk_mq_poll() long enough to trigger an RCU CPU stall, before io_uring gets back to io_iopoll_check() and its need_resched() check. Keep dm's ->poll_bio() bounded by forcing one-shot polling for target bios. The caller can invoke dm_poll_bio() again if it wants to keep polling, and it also gets a chance to reap completions or reschedule between passes.