From: Kamil Konieczny Subject: [PATCH v2] crypto: hash.h: Prevent use of req->result in ahash update Date: Wed, 07 Mar 2018 11:49:33 +0100 Message-ID: <7850c31c-8703-51fb-0710-3b4920935bfc@partner.samsung.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Bartlomiej Zolnierkiewicz , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org To: Herbert Xu Return-path: Content-language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org Prevent improper use of req->result field in ahash update, init, export and import functions in drivers code. A driver should use ahash request context if it needs to save internal state. Signed-off-by: Kamil Konieczny --- version 2: Change req->digest to req->result, as pointed out by Tom Lendacky include/crypto/hash.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/include/crypto/hash.h b/include/crypto/hash.h index 2d1849dffb80..76e432cab75d 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -74,7 +74,8 @@ struct ahash_request { * @init: **[mandatory]** Initialize the transformation context. Intended only to initialize the * state of the HASH transformation at the beginning. This shall fill in * the internal structures used during the entire duration of the whole - * transformation. No data processing happens at this point. + * transformation. No data processing happens at this point. Driver code + * implementation must not use req->result. * @update: **[mandatory]** Push a chunk of data into the driver for transformation. This * function actually pushes blocks of data from upper layers into the * driver, which then passes those to the hardware as seen fit. This @@ -83,7 +84,8 @@ struct ahash_request { * transformation. This function shall not modify the transformation * context, as this function may be called in parallel with the same * transformation object. Data processing can happen synchronously - * [SHASH] or asynchronously [AHASH] at this point. + * [SHASH] or asynchronously [AHASH] at this point. Driver must not use + * req->result. * @final: **[mandatory]** Retrieve result from the driver. This function finalizes the * transformation and retrieves the resulting hash from the driver and * pushes it back to upper layers. No data processing happens at this @@ -120,11 +122,12 @@ struct ahash_request { * you want to save partial result of the transformation after * processing certain amount of data and reload this partial result * multiple times later on for multiple re-use. No data processing - * happens at this point. + * happens at this point. Driver must not use req->result. * @import: Import partial state of the transformation. This function loads the * entire state of the ongoing transformation from a provided block of * data so the transformation can continue from this point onward. No - * data processing happens at this point. + * data processing happens at this point. Driver must not use + * req->result. * @halg: see struct hash_alg_common */ struct ahash_alg { -- 2.16.2