crypto: cryptd - Fix AEAD request context corruption

The AEAD version of cryptd uses the same context for its own state
as well as that of the child.  In doing so it did not maintain the
proper ordering, thus resulting in potential state corruption where
the child will overwrite the state stored by cryptd.

This patch fixes and also sets the request size properly.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/cryptd.c

@@ -688,16 +688,18 @@ static void cryptd_aead_crypt(struct aead_request *req,
 			int (*crypt)(struct aead_request *req))
 {
 	struct cryptd_aead_request_ctx *rctx;
+	crypto_completion_t compl;
+
 	rctx = aead_request_ctx(req);
+	compl = rctx->complete;
 
 	if (unlikely(err == -EINPROGRESS))
 		goto out;
 	aead_request_set_tfm(req, child);
 	err = crypt( req );
-	req->base.complete = rctx->complete;
 out:
 	local_bh_disable();
-	rctx->complete(&req->base, err);
+	compl(&req->base, err);
 	local_bh_enable();
 }
 
@@ -756,7 +758,9 @@ static int cryptd_aead_init_tfm(struct crypto_aead *tfm)
 		return PTR_ERR(cipher);
 
 	ctx->child = cipher;
-	crypto_aead_set_reqsize(tfm, sizeof(struct cryptd_aead_request_ctx));
+	crypto_aead_set_reqsize(
+		tfm, max((unsigned)sizeof(struct cryptd_aead_request_ctx),
+			 crypto_aead_reqsize(cipher)));
 	return 0;
 }
 
@@ -775,7 +779,7 @@ static int cryptd_create_aead(struct crypto_template *tmpl,
 	struct aead_alg *alg;
 	const char *name;
 	u32 type = 0;
-	u32 mask = 0;
+	u32 mask = CRYPTO_ALG_ASYNC;
 	int err;
 
 	cryptd_check_internal(tb, &type, &mask);