From: Kamil Konieczny Subject: Re: [PATCH] crypto: hash.h: Prevent use of req->digest in ahash update Date: Wed, 07 Mar 2018 11:22:22 +0100 Message-ID: <6fbd6e11-8c5c-4935-6f9e-0cea8f5dd178@partner.samsung.com> References: <0d5cfbd5-8675-290b-f840-d9121872f8da@amd.com> 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: Tom Lendacky , Herbert Xu Return-path: In-reply-to: <0d5cfbd5-8675-290b-f840-d9121872f8da@amd.com> Content-language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On 06.03.2018 19:04, Tom Lendacky wrote: > On 3/6/2018 5:45 AM, Kamil Konieczny wrote: >> Prevent improper use of req->digest field in ahash update, init, export and > > Shouldn't that be req->result (here and below)? Yes, it should, I will send version 2 soon, thank you. Best regards, Kamil Konieczny >> import functions in drivers code. A driver should use ahash request context >> if it needs to save internal state. >> >> Signed-off-by: Kamil Konieczny >> --- >> 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..e97c2e662d6a 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->digest. >> * @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->digest. >> * @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->digest. >> * @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->digest. >> * @halg: see struct hash_alg_common >> */ >> struct ahash_alg { >> > > >