CVE-2024-36908 blk-iocost: do not WARN if iocg was already offlined

In the Linux kernel, the following vulnerability has been resolved: blk-iocost: do not WARN if iocg was already offlined In iocgpaydebt, warn is triggered if 'activelist' is empty, which is intended to confirm iocg is active when it has debt. However, warn can be triggered during a blkcg or disk...

CVE-2024-36908

CVE-2024-36908 is a Linux kernel issue in the blk-iocost subsystem. The warning in iocg_pay_debt can be triggered during blkcg or disk removal when iocg_waitq_timer_fn() runs, producing a meaningless warning. The patch adds a guard to skip the warn if the iocg was already offlined, since the iocg...