From patchwork Mon Dec 28 12:50:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 354478 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDFB3C433DB for ; Mon, 28 Dec 2020 15:56:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5A6920829 for ; Mon, 28 Dec 2020 15:56:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389185AbgL1Nee (ORCPT ); Mon, 28 Dec 2020 08:34:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:34738 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391142AbgL1Ned (ORCPT ); Mon, 28 Dec 2020 08:34:33 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id BDE75207B2; Mon, 28 Dec 2020 13:34:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609162458; bh=O9qS/MAmnFhi9/af/HnY3Uf21tkvjHdUH0xv1zmydWo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZmjWvoxszdqRSi27Udtmi+mu8s4MQ3yRZAAUD/c6fw1g58k14dGq/DXXau+GY3OTw oBJoXwJTC9GHen3Ml3lj3LjqsV+vnZM7T+HPccdIySI9o6U/8hR1kB/Ok7SemEbLWI bvtb1uptmod6oP8CSkp9GPK0Rgkqauef6ixM3/GI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shyam Prasad N , Pavel Shilovsky , Steve French Subject: [PATCH 4.19 310/346] SMB3.1.1: do not log warning message if server doesnt populate salt Date: Mon, 28 Dec 2020 13:50:29 +0100 Message-Id: <20201228124934.778573319@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124919.745526410@linuxfoundation.org> References: <20201228124919.745526410@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Steve French commit 7955f105afb6034af344038d663bc98809483cdd upstream. In the negotiate protocol preauth context, the server is not required to populate the salt (although it is done by most servers) so do not warn on mount. We retain the checks (warn) that the preauth context is the minimum size and that the salt does not exceed DataLength of the SMB response. Although we use the defaults in the case that the preauth context response is invalid, these checks may be useful in the future as servers add support for additional mechanisms. CC: Stable Reviewed-by: Shyam Prasad N Reviewed-by: Pavel Shilovsky Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smb2pdu.c | 7 +++++-- fs/cifs/smb2pdu.h | 14 +++++++++++--- 2 files changed, 16 insertions(+), 5 deletions(-) --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -406,8 +406,8 @@ build_preauth_ctxt(struct smb2_preauth_n pneg_ctxt->ContextType = SMB2_PREAUTH_INTEGRITY_CAPABILITIES; pneg_ctxt->DataLength = cpu_to_le16(38); pneg_ctxt->HashAlgorithmCount = cpu_to_le16(1); - pneg_ctxt->SaltLength = cpu_to_le16(SMB311_SALT_SIZE); - get_random_bytes(pneg_ctxt->Salt, SMB311_SALT_SIZE); + pneg_ctxt->SaltLength = cpu_to_le16(SMB311_LINUX_CLIENT_SALT_SIZE); + get_random_bytes(pneg_ctxt->Salt, SMB311_LINUX_CLIENT_SALT_SIZE); pneg_ctxt->HashAlgorithms = SMB2_PREAUTH_INTEGRITY_SHA512; } @@ -461,6 +461,9 @@ static void decode_preauth_context(struc if (len < MIN_PREAUTH_CTXT_DATA_LEN) { printk_once(KERN_WARNING "server sent bad preauth context\n"); return; + } else if (len < MIN_PREAUTH_CTXT_DATA_LEN + le16_to_cpu(ctxt->SaltLength)) { + pr_warn_once("server sent invalid SaltLength\n"); + return; } if (le16_to_cpu(ctxt->HashAlgorithmCount) != 1) printk_once(KERN_WARNING "illegal SMB3 hash algorithm count\n"); --- a/fs/cifs/smb2pdu.h +++ b/fs/cifs/smb2pdu.h @@ -257,12 +257,20 @@ struct smb2_neg_context { /* Followed by array of data */ } __packed; -#define SMB311_SALT_SIZE 32 +#define SMB311_LINUX_CLIENT_SALT_SIZE 32 /* Hash Algorithm Types */ #define SMB2_PREAUTH_INTEGRITY_SHA512 cpu_to_le16(0x0001) #define SMB2_PREAUTH_HASH_SIZE 64 -#define MIN_PREAUTH_CTXT_DATA_LEN (SMB311_SALT_SIZE + 6) +/* + * SaltLength that the server send can be zero, so the only three required + * fields (all __le16) end up six bytes total, so the minimum context data len + * in the response is six bytes which accounts for + * + * HashAlgorithmCount, SaltLength, and 1 HashAlgorithm. + */ +#define MIN_PREAUTH_CTXT_DATA_LEN 6 + struct smb2_preauth_neg_context { __le16 ContextType; /* 1 */ __le16 DataLength; @@ -270,7 +278,7 @@ struct smb2_preauth_neg_context { __le16 HashAlgorithmCount; /* 1 */ __le16 SaltLength; __le16 HashAlgorithms; /* HashAlgorithms[0] since only one defined */ - __u8 Salt[SMB311_SALT_SIZE]; + __u8 Salt[SMB311_LINUX_CLIENT_SALT_SIZE]; } __packed; /* Encryption Algorithms Ciphers */