aesni: Avoid a potential out-of-bounds load in aes_encrypt_icm()
Given a partial block at the end of a payload, aes_encrypt_icm() would
perform a 16-byte load of the residual into a temporary variable. This
is unsafe in principle since the full block may cross a page boundary.
Fix the problem by copying the residual into a stack buffer first.
Reported by: firstname.lastname@example.org
Reported by: email@example.com
Reported by: firstname.lastname@example.org
Reported by: email@example.com
Reviewed by: cem, jhb
Sponsored by: The FreeBSD Foundation
(cherry picked from commit 564b6aa7fccd98654207447f870b82659b895e7b)