Kernel compromise via writeback workqueue use-after-free

Use-after-free in Linux Kernel allows local users to compromise kernel memory through a writeback workqueue race condition. The inode_switch_wbs_work_fn() loop can empty switch_wbs_ctxs while switch_work remains pending, allowing its backing writeback structure to be freed before the queued work runs. Triggering requires local low-privileged access and race timing; successful exploitation permits disclosure or modification of kernel data or a system interruption.