crypto: cryptd - initialize child shash_desc on import

When calling .import() on a cryptd ahash_request, the structure members
that describe the child transform in the shash_desc need to be initialized
like they are when calling .init()

Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/cryptd.c

@@ -631,9 +631,14 @@ static int cryptd_hash_export(struct ahash_request *req, void *out)
 
 static int cryptd_hash_import(struct ahash_request *req, const void *in)
 {
-	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct shash_desc *desc = cryptd_shash_desc(req);
 
-	return crypto_shash_import(&rctx->desc, in);
+	desc->tfm = ctx->child;
+	desc->flags = req->base.flags;
+
+	return crypto_shash_import(desc, in);
 }
 
 static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,