This closes a hole pointed out by Thor Lancelot Simon on tech-kern ~3
years ago.
The problem was with running binaries from remote storage, where our
kernel (and Veriexec) has no control over any changes to files.
An attacker could, after the fingerprint has been verified and
program loaded to memory, inject malicious code into the backing
store on the remote storage, followed by a forced flush, causing
a page-in of the malicious data from backing store, bypassing
integrity checks.
Initial implementation by Brett Lymn.