An out-of-bounds (OOB) memory write flaw was found in list_devices in
drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel
before 5.12. A bound check failure allows an attacker with special user
(CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to
a system crash or a leak of internal kernel information. The highest threat
from this vulnerability is to system availability.

Dan Carpenter discovered that the block device manager (dm) implementation
in the Linux kernel contained a buffer overflow in the ioctl for listing
devices. A privileged local attacker could use this to cause a denial of
service (system crash).