From patchwork Sat Jun 23 17:52:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paulo Alcantara (SUSE)" X-Patchwork-Id: 10483797 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 4ACB86023A for ; Sat, 23 Jun 2018 17:53:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 44DEA28971 for ; Sat, 23 Jun 2018 17:53:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3734B289D0; Sat, 23 Jun 2018 17:53:00 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham 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 AE96928971 for ; Sat, 23 Jun 2018 17:52:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751838AbeFWRw7 (ORCPT ); Sat, 23 Jun 2018 13:52:59 -0400 Received: from mail.paulo.ac ([34.238.86.106]:33286 "EHLO mail.paulo.ac" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbeFWRw6 (ORCPT ); Sat, 23 Jun 2018 13:52:58 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.paulo.ac (Postfix) with ESMTP id 026EBC76529; Sat, 23 Jun 2018 17:52:58 +0000 (UTC) X-Virus-Scanned: amavisd-new at paulo.ac Authentication-Results: mail.paulo.ac (amavisd-new); dkim=pass (1024-bit key) header.d=paulo.ac Received: from mail.paulo.ac ([127.0.0.1]) by localhost (mail.paulo.ac [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YQWVHUUg0BV2; Sat, 23 Jun 2018 17:52:56 +0000 (UTC) Received: from localhost.localdomain (189.27.253.103.dynamic.adsl.gvt.net.br [189.27.253.103]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.paulo.ac (Postfix) with ESMTPSA id 9C3B7C76528; Sat, 23 Jun 2018 17:52:54 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.paulo.ac 9C3B7C76528 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=paulo.ac; s=default; t=1529776376; bh=6Tz468UYvoQk5R6MirY+J0MY5zOxCHXaTmMaPnKTTFI=; h=From:To:Cc:Subject:Date:From; b=gfryMSDVPSdZOnnbJNljKwBKjlfAH9Jbz6tSK1xO/OyhYe3v3yVG5xoUqDdZbc64Y 3nVQwQWZWvl9xj5XE0wnf/1m3ssq655yadddKlsP2oeb3vkmiAj3c2uTQxw/R9e9I1 iS/VpCARWEJYGi9cc+EM8SLNiBBkT5H/Uj41uAYY= From: Paulo Alcantara To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, Paulo Alcantara , Paulo Alcantara Subject: [PATCH 1/3] cifs: Fix validation of signed data in smb3+ Date: Sat, 23 Jun 2018 14:52:23 -0300 Message-Id: <20180623175225.31162-1-paulo@paulo.ac> X-Mailer: git-send-email 2.17.1 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We failed to validate signed data returned by the server because __cifs_calc_signature() now expects to sign the actual data in iov but we were also passing down the rfc1002 length. Fix smb3_calc_signature() to calculate signature of rfc1002 length prior to passing only the actual data iov[1-N] to __cifs_calc_signature(). In addition, there are a few cases where no rfc1002 lenght is passed so we make sure there's one (iov_len == 4). Signed-off-by: Paulo Alcantara --- fs/cifs/smb2transport.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c index 50592976dcb4..1af46ca5a951 100644 --- a/fs/cifs/smb2transport.c +++ b/fs/cifs/smb2transport.c @@ -408,12 +408,14 @@ generate_smb311signingkey(struct cifs_ses *ses) int smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) { - int rc = 0; + int rc; unsigned char smb3_signature[SMB2_CMACAES_SIZE]; unsigned char *sigptr = smb3_signature; struct kvec *iov = rqst->rq_iov; struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base; struct cifs_ses *ses; + struct shash_desc *shash = &server->secmech.sdesccmacaes->shash; + struct smb_rqst drqst; ses = smb2_find_smb_ses(server, shdr->SessionId); if (!ses) { @@ -425,8 +427,7 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE); rc = crypto_shash_setkey(server->secmech.cmacaes, - ses->smb3signingkey, SMB2_CMACAES_SIZE); - + ses->smb3signingkey, SMB2_CMACAES_SIZE); if (rc) { cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__); return rc; @@ -437,15 +438,33 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) * so unlike smb2 case we do not have to check here if secmech are * initialized */ - rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash); + rc = crypto_shash_init(shash); if (rc) { cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__); return rc; } - rc = __cifs_calc_signature(rqst, server, sigptr, - &server->secmech.sdesccmacaes->shash); + /* + * For SMB2+, __cifs_calc_signature() expects to sign only the actual + * data, that is, iov[0] should not contain a rfc1002 length. + * + * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to + * __cifs_calc_signature(). + */ + drqst = *rqst; + if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) { + rc = crypto_shash_update(shash, iov[0].iov_base, + iov[0].iov_len); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with payload\n", + __func__); + return rc; + } + drqst.rq_iov++; + drqst.rq_nvec--; + } + rc = __cifs_calc_signature(&drqst, server, sigptr, shash); if (!rc) memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);