From patchwork Wed Dec 14 02:48:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 9473637 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BFEF160762 for ; Wed, 14 Dec 2016 02:48:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B46BA286D5 for ; Wed, 14 Dec 2016 02:48:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A9160286E3; Wed, 14 Dec 2016 02:48:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 609B0286D5 for ; Wed, 14 Dec 2016 02:48:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753311AbcLNCsM (ORCPT ); Tue, 13 Dec 2016 21:48:12 -0500 Received: from mail.kernel.org ([198.145.29.136]:51908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752532AbcLNCsL (ORCPT ); Tue, 13 Dec 2016 21:48:11 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 45FD720430; Wed, 14 Dec 2016 02:48:09 +0000 (UTC) Received: from localhost (c-71-202-137-17.hsd1.ca.comcast.net [71.202.137.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 46C37203F3; Wed, 14 Dec 2016 02:48:08 +0000 (UTC) From: Andy Lutomirski To: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, dhowells@redhat.com, keyrings@vger.kernel.org Cc: Eric Biggers , linux-crypto@vger.kernel.org, Herbert Xu , Stephan Mueller , Andy Lutomirski Subject: [PATCH v2] keys/encrypted: Fix two crypto-on-the-stack bugs Date: Tue, 13 Dec 2016 18:48:07 -0800 Message-Id: <627e948e37314c13a67c90917386c814c56b8e20.1481683609.git.luto@kernel.org> X-Mailer: git-send-email 2.9.3 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The driver put a constant buffer of all zeros on the stack and pointed a scatterlist entry at it in two places. This doesn't work with virtual stacks. Use ZERO_PAGE instead. Cc: stable@vger.kernel.org # 4.9 only Reported-by: Eric Biggers Signed-off-by: Andy Lutomirski --- security/keys/encrypted-keys/encrypted.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 17a06105ccb6..e963160ed26a 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -481,7 +481,6 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload, unsigned int encrypted_datalen; u8 iv[AES_BLOCK_SIZE]; unsigned int padlen; - char pad[16]; int ret; encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); @@ -493,11 +492,10 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload, goto out; dump_decrypted_data(epayload); - memset(pad, 0, sizeof pad); sg_init_table(sg_in, 2); sg_set_buf(&sg_in[0], epayload->decrypted_data, epayload->decrypted_datalen); - sg_set_buf(&sg_in[1], pad, padlen); + sg_set_page(&sg_in[1], ZERO_PAGE(0), padlen, 0); sg_init_table(sg_out, 1); sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen); @@ -584,7 +582,6 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload, struct skcipher_request *req; unsigned int encrypted_datalen; u8 iv[AES_BLOCK_SIZE]; - char pad[16]; int ret; encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); @@ -594,13 +591,12 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload, goto out; dump_encrypted_data(epayload, encrypted_datalen); - memset(pad, 0, sizeof pad); sg_init_table(sg_in, 1); sg_init_table(sg_out, 2); sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen); sg_set_buf(&sg_out[0], epayload->decrypted_data, epayload->decrypted_datalen); - sg_set_buf(&sg_out[1], pad, sizeof pad); + sg_set_buf(&sg_out[1], empty_zero_page, 16); memcpy(iv, epayload->iv, sizeof(iv)); skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv);