A flaw null pointer dereference in the Linux kernel UDF file system
functionality was found in the way user triggers udf_file_write_iter
function for the malicious UDF image. A local user could use this flaw to
crash the system. Actual from Linux kernel 4.2-rc1 till 5.17-rc2.

It was discovered that the UDF file system implementation in the Linux
kernel could attempt to dereference a null pointer in some situations. An
attacker could use this to construct a malicious UDF image that, when
mounted and operated on, could cause a denial of service (system crash).