From patchwork Tue Oct 17 12:47:17 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Aur=C3=A9lien_Aptel?= X-Patchwork-Id: 826948 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3yGZj4133Yz9rxl for ; Tue, 17 Oct 2017 23:47:36 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761884AbdJQMre (ORCPT ); Tue, 17 Oct 2017 08:47:34 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:49231 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761878AbdJQMrc (ORCPT ); Tue, 17 Oct 2017 08:47:32 -0400 Received: from localhost (charybdis-ext.suse.de [195.135.221.2]) by smtp.nue.novell.com with ESMTP (TLS encrypted); Tue, 17 Oct 2017 14:47:29 +0200 From: Aurelien Aptel To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, Aurelien Aptel Subject: [PATCH] CIFS: do not send invalid input buffer on QUERY_INFO requests Date: Tue, 17 Oct 2017 14:47:17 +0200 Message-Id: <20171017124717.25955-1-aaptel@suse.com> X-Mailer: git-send-email 2.12.3 In-Reply-To: References: Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org query_info() doesn't use the InputBuffer field of the QUERY_INFO request, therefore according to [MS-SMB2] it must: a) set the InputBufferOffset to 0 b) send a zero-length InputBuffer Doing a) is trivial but b) is a bit more tricky. The packet is allocated according to it's StructureSize, which takes into account an extra 1 byte buffer which we don't need here. StructureSize fields must have constant values no matter the actual length of the whole packet so we can't just edit that constant. Both the NetBIOS-over-TCP message length ("rfc1002 length") L and the iovec length L' have to be updated. Since L' is computed from L we just update L by decrementing it by one. Signed-off-by: Aurelien Aptel --- fs/cifs/smb2pdu.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 6f0e6343c15e..b927e131f997 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2191,9 +2191,13 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, req->PersistentFileId = persistent_fid; req->VolatileFileId = volatile_fid; req->AdditionalInformation = cpu_to_le32(additional_info); - /* 4 for rfc1002 length field and 1 for Buffer */ - req->InputBufferOffset = - cpu_to_le16(sizeof(struct smb2_query_info_req) - 1 - 4); + + /* + * We do not use the input buffer (do not send extra byte) + */ + req->InputBufferOffset = 0; + inc_rfc1001_len(req, -1); + req->OutputBufferLength = cpu_to_le32(output_len); iov[0].iov_base = (char *)req;