tree 8098e899bb23058ec1f8eef39a084bd2cfaffead
parent 3f66393f50143ccfc3b06b13e2f728a246a23f99
author Kees Cook <keescook@chromium.org> 1533676720 -0700
committer Rishabh Bhatnagar <rishabhb@codeaurora.org> 1541613467 -0800

crypto: api - Introduce generic max blocksize and alignmask

In the quest to remove all stack VLA usage from the kernel[1], this
exposes a new general upper bound on crypto blocksize and alignmask
(higher than for the existing cipher limits) for VLA removal,
and introduces new checks.

At present, the highest cra_alignmask in the kernel is 63. The highest
cra_blocksize is 144 (SHA3_224_BLOCK_SIZE, 18 8-byte words). For the
new blocksize limit, I went with 160 (20 8-byte words).

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Change-Id: Icee27c45f542a9de25310b193c5bd08bc236996e
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Git-Repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-Commit: a9f7f88a12f1494deca1fd9e173c7ae886d14f91
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>