Re: Doing crypto in small stack buffers (bluetooth vs vmalloc-stack crash, etc)

On Tue, Jun 21, 2016 at 5:42 PM, Herbert Xu [off-list ref] wrote:

On Tue, Jun 21, 2016 at 10:43:40AM -0700, Andy Lutomirski wrote:

quoted

Is there a straightforward way that bluetooth and, potentially, other
drivers can just do synchronous crypto in a small buffer specified by
its virtual address?  The actual cryptography part of the crypto code
already works this way, but I can't find an API for it.

Yes, single block users should use crypto_cipher_encrypt_one, an
example would be drivers/md/dm-crypt.c.

Aha!  I expected something like that to exist, but I couldn't find it.
I'll change the two offenders I've found so far to use it.

--Andy