From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757598AbcAPAkg (ORCPT ); Fri, 15 Jan 2016 19:40:36 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:36639 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756411AbcAPAF5 (ORCPT ); Fri, 15 Jan 2016 19:05:57 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Jason A. Donenfeld" , Herbert Xu , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 194/305] crypto: skcipher - Copy iv from desc even for 0-len walks Date: Fri, 15 Jan 2016 16:00:08 -0800 Message-Id: <1452902519-2754-195-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1452902519-2754-1-git-send-email-kamal@canonical.com> References: <1452902519-2754-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: "Jason A. Donenfeld" commit 70d906bc17500edfa9bdd8c8b7e59618c7911613 upstream. Some ciphers actually support encrypting zero length plaintexts. For example, many AEAD modes support this. The resulting ciphertext for those winds up being only the authentication tag, which is a result of the key, the iv, the additional data, and the fact that the plaintext had zero length. The blkcipher constructors won't copy the IV to the right place, however, when using a zero length input, resulting in some significant problems when ciphers call their initialization routines, only to find that the ->iv parameter is uninitialized. One such example of this would be using chacha20poly1305 with a zero length input, which then calls chacha20, which calls the key setup routine, which eventually OOPSes due to the uninitialized ->iv member. Signed-off-by: Jason A. Donenfeld Signed-off-by: Herbert Xu Signed-off-by: Kamal Mostafa --- crypto/ablkcipher.c | 2 +- crypto/blkcipher.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c index b4ffc5b..e5b5721 100644 --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -277,12 +277,12 @@ static int ablkcipher_walk_first(struct ablkcipher_request *req, if (WARN_ON_ONCE(in_irq())) return -EDEADLK; + walk->iv = req->info; walk->nbytes = walk->total; if (unlikely(!walk->total)) return 0; walk->iv_buffer = NULL; - walk->iv = req->info; if (unlikely(((unsigned long)walk->iv & alignmask))) { int err = ablkcipher_copy_iv(walk, tfm, alignmask); diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c index 11b9814..8cc1622 100644 --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -326,12 +326,12 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc, if (WARN_ON_ONCE(in_irq())) return -EDEADLK; + walk->iv = desc->info; walk->nbytes = walk->total; if (unlikely(!walk->total)) return 0; walk->buffer = NULL; - walk->iv = desc->info; if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { int err = blkcipher_copy_iv(walk); if (err) -- 1.9.1