From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Jason A. Donenfeld" , Herbert Xu Subject: [PATCH 4.3 008/200] crypto: skcipher - Copy iv from desc even for 0-len walks Date: Sun, 14 Feb 2016 14:20:15 -0800 Message-Id: <20160214222217.405347500@linuxfoundation.org> In-Reply-To: <20160214222217.084543173@linuxfoundation.org> References: <20160214222217.084543173@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.3-stable review patch. If anyone has any objections, please let me know. ------------------ 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: Greg Kroah-Hartman --- crypto/ablkcipher.c | 2 +- crypto/blkcipher.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -277,12 +277,12 @@ static int ablkcipher_walk_first(struct 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); --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -326,12 +326,12 @@ static int blkcipher_walk_first(struct b 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)