From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51332 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754983AbdKMNDA (ORCPT ); Mon, 13 Nov 2017 08:03:00 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Romain Izard , Tudor Ambarus , Herbert Xu Subject: [PATCH 4.9 57/87] crypto: ccm - preserve the IV buffer Date: Mon, 13 Nov 2017 13:56:14 +0100 Message-Id: <20171113125620.606802451@linuxfoundation.org> In-Reply-To: <20171113125615.304035578@linuxfoundation.org> References: <20171113125615.304035578@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Romain Izard commit 441f99c90497e15aa3ad1dbabd56187e29614348 upstream. The IV buffer used during CCM operations is used twice, during both the hashing step and the ciphering step. When using a hardware accelerator that updates the contents of the IV buffer at the end of ciphering operations, the value will be modified. In the decryption case, the subsequent setup of the hashing algorithm will interpret the updated IV instead of the original value, which can lead to out-of-bounds writes. Reuse the idata buffer, only used in the hashing step, to preserve the IV's value during the ciphering step in the decryption case. Signed-off-by: Romain Izard Reviewed-by: Tudor Ambarus Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/ccm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/crypto/ccm.c +++ b/crypto/ccm.c @@ -413,7 +413,7 @@ static int crypto_ccm_decrypt(struct aea unsigned int cryptlen = req->cryptlen; u8 *authtag = pctx->auth_tag; u8 *odata = pctx->odata; - u8 *iv = req->iv; + u8 *iv = pctx->idata; int err; cryptlen -= authsize; @@ -429,6 +429,8 @@ static int crypto_ccm_decrypt(struct aea if (req->src != req->dst) dst = pctx->dst; + memcpy(iv, req->iv, 16); + skcipher_request_set_tfm(skreq, ctx->ctr); skcipher_request_set_callback(skreq, pctx->flags, crypto_ccm_decrypt_done, req);