From patchwork Thu Oct 24 11:27:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 1182981 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="ihtJKcvf"; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46zR4R3cXDz9sPh for ; Thu, 24 Oct 2019 23:14:15 +1100 (AEDT) Received: from localhost ([::1]:40724 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iNc0K-0000on-St for incoming@patchwork.ozlabs.org; Thu, 24 Oct 2019 08:14:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39350) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iNbHu-0003Pp-Ct for qemu-devel@nongnu.org; Thu, 24 Oct 2019 07:28:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iNbHs-0008UA-Nr for qemu-devel@nongnu.org; Thu, 24 Oct 2019 07:28:18 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:41147 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iNbHq-0008Tb-5P for qemu-devel@nongnu.org; Thu, 24 Oct 2019 07:28:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571916493; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Kc/gbo+upybElFbY3/lui49elaqZGdHA6I+6dPD8EcM=; b=ihtJKcvfyxYZ9bPKub7BTVUp1SUWPHh5cxSmlzEQkcsksKxZBAovxR0vGBuOLYgrih9Cq0 UCKkF/lOd9jw0veBkvN34ZuJfEavsdoEgLan4Farq571rRTjByHFzALP4D5q4qYoUUkim8 TwgcihL3dWDnu92nUCGa55iF7WBCNuY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-184-uPdozyFLNn2UnDCjrxYpvA-1; Thu, 24 Oct 2019 07:28:09 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 51B98107AD31; Thu, 24 Oct 2019 11:28:08 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-117-248.ams2.redhat.com [10.36.117.248]) by smtp.corp.redhat.com (Postfix) with ESMTP id CB4A74524; Thu, 24 Oct 2019 11:28:05 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, renzhen@linux.alibaba.com, eguan@linux.alibaba.com, ganesh.mahalingam@intel.com, m.mizuma@jp.fujitsu.com, mszeredi@redhat.com, misono.tomohiro@jp.fujitsu.com, tao.peng@linux.alibaba.com, piaojun@huawei.com, stefanha@redhat.com, vgoyal@redhat.com, mst@redhat.com, berrange@redhat.com Subject: [PATCH 11/25] virtiofsd: validate input buffer sizes in do_write_buf() Date: Thu, 24 Oct 2019 12:27:04 +0100 Message-Id: <20191024112718.34657-12-dgilbert@redhat.com> In-Reply-To: <20191024112718.34657-1-dgilbert@redhat.com> References: <20191024112718.34657-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: uPdozyFLNn2UnDCjrxYpvA-1 X-Mimecast-Spam-Score: 0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Stefan Hajnoczi There is a small change in behavior: if fuse_write_in->size doesn't match the input buffer size then the request is failed. Previously write requests with 1 fuse_buf element would truncate to fuse_write_in->size. Signed-off-by: Stefan Hajnoczi --- contrib/virtiofsd/fuse_lowlevel.c | 62 +++++++++++++++++++------------ 1 file changed, 38 insertions(+), 24 deletions(-) diff --git a/contrib/virtiofsd/fuse_lowlevel.c b/contrib/virtiofsd/fuse_lowlevel.c index 2bd2ba00b9..7927348398 100644 --- a/contrib/virtiofsd/fuse_lowlevel.c +++ b/contrib/virtiofsd/fuse_lowlevel.c @@ -1006,7 +1006,8 @@ static void do_write(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) fuse_reply_err(req, ENOSYS); } -static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg, +static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, + struct fuse_mbuf_iter *iter, struct fuse_bufvec *ibufv) { struct fuse_session *se = req->se; @@ -1015,34 +1016,36 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg, .buf[0] = ibufv->buf[0], .count = 1, }; - struct fuse_write_in *arg = (struct fuse_write_in *) inarg; + struct fuse_write_in *arg; + size_t arg_size = sizeof(*arg); struct fuse_file_info fi; memset(&fi, 0, sizeof(fi)); + + if (se->conn.proto_minor < 9) { + arg_size = FUSE_COMPAT_WRITE_IN_SIZE; + } + + arg = fuse_mbuf_iter_advance(iter, arg_size); + if (!arg) { + fuse_reply_err(req, EINVAL); + return; + } + + /* Only access non-compat fields here! */ + if (se->conn.proto_minor >= 9) { + fi.lock_owner = arg->lock_owner; + fi.flags = arg->flags; + } + fi.fh = arg->fh; fi.writepage = arg->write_flags & FUSE_WRITE_CACHE; if (ibufv->count == 1) { - if (se->conn.proto_minor < 9) { - tmpbufv.buf[0].mem = ((char *) arg) + FUSE_COMPAT_WRITE_IN_SIZE; - tmpbufv.buf[0].size -= sizeof(struct fuse_in_header) + - FUSE_COMPAT_WRITE_IN_SIZE; - assert(!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD)); - } else { - fi.lock_owner = arg->lock_owner; - fi.flags = arg->flags; - if (!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD)) - tmpbufv.buf[0].mem = PARAM(arg); - - tmpbufv.buf[0].size -= sizeof(struct fuse_in_header) + - sizeof(struct fuse_write_in); - } - if (tmpbufv.buf[0].size < arg->size) { - fuse_log(FUSE_LOG_ERR, "fuse: do_write_buf: buffer size too small\n"); - fuse_reply_err(req, EIO); - return; - } - tmpbufv.buf[0].size = arg->size; + assert(!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD)); + tmpbufv.buf[0].mem = ((char *) arg) + arg_size; + tmpbufv.buf[0].size -= sizeof(struct fuse_in_header) + + arg_size; pbufv = &tmpbufv; } else { // Input bufv contains the headers in the first element @@ -1050,6 +1053,12 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg, ibufv->buf[0].size = 0; } + if (fuse_buf_size(pbufv) != arg->size) { + fuse_log(FUSE_LOG_ERR, "fuse: do_write_buf: buffer size doesn't match arg->size\n"); + fuse_reply_err(req, EIO); + return; + } + se->op.write_buf(req, nodeid, pbufv, arg->offset, &fi); } @@ -2002,12 +2011,17 @@ void fuse_session_process_buf_int(struct fuse_session *se, struct fuse_bufvec *bufv, struct fuse_chan *ch) { const struct fuse_buf *buf = bufv->buf; + struct fuse_mbuf_iter iter = FUSE_MBUF_ITER_INIT(buf); struct fuse_in_header *in; const void *inarg; struct fuse_req *req; int err; - in = buf->mem; + /* The first buffer must be a memory buffer */ + assert(!(buf->flags & FUSE_BUF_IS_FD)); + + in = fuse_mbuf_iter_advance(&iter, sizeof(*in)); + assert(in); /* caller guarantees the input buffer is large enough */ if (se->debug) { fuse_log(FUSE_LOG_DEBUG, @@ -2074,7 +2088,7 @@ void fuse_session_process_buf_int(struct fuse_session *se, inarg = (void *) &in[1]; if (in->opcode == FUSE_WRITE && se->op.write_buf) - do_write_buf(req, in->nodeid, inarg, bufv); + do_write_buf(req, in->nodeid, &iter, bufv); else fuse_ll_ops[in->opcode].func(req, in->nodeid, inarg);