CVE-2022-50086: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50086 is a vulnerability in the Linux kernel's block subsystem, specifically related to the rqqos functionality. The issue was discovered when concurrent writes to io.cost.qos could cause the same type of rqqos to be added to one disk multiple times (NVD, Wiz).

The vulnerability occurs when io.cost.qos file is written by two CPUs concurrently, allowing rqqos to be added to one disk twice. This results in two iocs being enabled and running on one disk, with different iocgs on their active lists. In the ioctimerfn function, because the iocgs from two iocs have the same root iocg, the root iocg's walklist may be overwritten, leading to list add/del corruptions in building or destroying the inner_walk list (NVD).

The vulnerability can result in list add/del corruptions of innerwalk list in ioctimer_fn, potentially affecting system stability and disk I/O management (Wiz).

The issue has been resolved by implementing a fix that prevents the same type of rqqos from being added more than once. This aligns with the default behavior of the blk-rq-qos framework, which typically works with one instance for one type rqqos per queue (Wiz).