In the Linux kernel, the following vulnerability has been resolved:
blk-mq: fix NULL dereference on q->elevator in blk_mq_elv_switch_none
After grabbing q->sysfs_lock, q->elevator may become NULL because of elevator switch.
Fix the NULL dereference on q->elevator by checking it with lock.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:H5.5/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H