CVE-2022-49400 md: Don't set mddev private to NULL in raid0 pers->free

In the Linux kernel, the following vulnerability has been resolved: md: Don't set mddev private to NULL in raid0 pers-free In normal stop process, it does like this: domdstop | mdstop pers-free; mddev-private=NULL | mdfree free mddev mdstop sets mddev-private to NULL after pers-free. The raid...