On Mon, Jun 25, 2018 at 02:10:26PM -0700, Kees Cook wrote:

In the quest to remove all stack VLA usage from the kernel[1], this
caps the skcipher request size similar to other limits and adds a
sanity check at registration. In a manual review of the callers of
crypto_skcipher_set_reqsize(), the largest was 384:

4	sun4i_cipher_req_ctx
6	safexcel_cipher_req
8	cryptd_skcipher_request_ctx
80	cipher_req_ctx
80	skcipher_request
96	crypto_rfc3686_req_ctx
104	nitrox_kcrypt_request
144	mv_cesa_skcipher_std_req
384	rctx

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

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Kees Cook <redacted>

This has the same issue as the ahash reqsize patch.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt