From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752545AbcI1JIp (ORCPT ); Wed, 28 Sep 2016 05:08:45 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57403 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752127AbcI1JIV (ORCPT ); Wed, 28 Sep 2016 05:08:21 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, xiakaixu , Ard Biesheuvel , Herbert Xu Subject: [PATCH 4.7 02/69] crypto: arm64/aes-ctr - fix NULL dereference in tail processing Date: Wed, 28 Sep 2016 11:04:44 +0200 Message-Id: <20160928090445.147851085@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160928090445.054716307@linuxfoundation.org> References: <20160928090445.054716307@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ard Biesheuvel commit 2db34e78f126c6001d79d3b66ab1abb482dc7caa upstream. The AES-CTR glue code avoids calling into the blkcipher API for the tail portion of the walk, by comparing the remainder of walk.nbytes modulo AES_BLOCK_SIZE with the residual nbytes, and jumping straight into the tail processing block if they are equal. This tail processing block checks whether nbytes != 0, and does nothing otherwise. However, in case of an allocation failure in the blkcipher layer, we may enter this code with walk.nbytes == 0, while nbytes > 0. In this case, we should not dereference the source and destination pointers, since they may be NULL. So instead of checking for nbytes != 0, check for (walk.nbytes % AES_BLOCK_SIZE) != 0, which implies the former in non-error conditions. Fixes: 49788fe2a128 ("arm64/crypto: AES-ECB/CBC/CTR/XTS using ARMv8 NEON and Crypto Extensions") Reported-by: xiakaixu Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- arch/arm64/crypto/aes-glue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/crypto/aes-glue.c +++ b/arch/arm64/crypto/aes-glue.c @@ -216,7 +216,7 @@ static int ctr_encrypt(struct blkcipher_ err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); } - if (nbytes) { + if (walk.nbytes % AES_BLOCK_SIZE) { u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE; u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE; u8 __aligned(8) tail[AES_BLOCK_SIZE];