CVE-2026-64578 ksmbd: validate compound request size before reading StructureSize2

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate compound request size before reading StructureSize2 When ksmbd validates a compound chained SMB2 request, ksmbdsmb2checkmessage reads pdu-StructureSize2 without first checking that the compound element is large...