From patchwork Thu Jan 23 16:45:26 2020 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: 11349161 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 85BC092A for ; Thu, 23 Jan 2020 19:49:20 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 5A54021D7D for ; Thu, 23 Jan 2020 19:49:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IHg8dBu9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A54021D7D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:60602 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuiTf-000298-Ca for patchwork-qemu-devel@patchwork.kernel.org; Thu, 23 Jan 2020 14:49:19 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41310) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iufdx-0004yv-M3 for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:47:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iufdw-0006YC-Av for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:47:45 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:45736 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 1iufdw-0006Xu-7u for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:47:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579798063; 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=a7J2d+/qEC/4s8KwV2sf+Fq1jzRcegakEDeWcp+uogY=; b=IHg8dBu9iStMP0EyB6jqv1mPJGufVqzv4WIxKmlDgIz2UfSj8cZ9aaGnsLtZnw+oP+w8qR 8FHrbN1rO5ifNiQNj73zGnFKNhdHDBRJybkhjXlKJsQh5YD8BZMKTV0Y9p6/kDClV514n4 FqdPqjm8kU6fJcmko3NkQSsFjopCAws= 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-210-t0lx9W7vM0mLE8j-_FIxDA-1; Thu, 23 Jan 2020 11:47:42 -0500 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 72C6C8024F9 for ; Thu, 23 Jan 2020 16:47:41 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-110.ams2.redhat.com [10.36.116.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id BDB0628998; Thu, 23 Jan 2020 16:47:40 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com Subject: [PULL 044/108] virtiofsd: validate input buffer sizes in do_write_buf() Date: Thu, 23 Jan 2020 16:45:26 +0000 Message-Id: <20200123164630.91498-45-dgilbert@redhat.com> In-Reply-To: <20200123164630.91498-1-dgilbert@redhat.com> References: <20200123164630.91498-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: t0lx9W7vM0mLE8j-_FIxDA-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] 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+patchwork-qemu-devel=patchwork.kernel.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 Reviewed-by: Sergio Lopez Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/fuse_lowlevel.c | 49 ++++++++++++++++++++------------- 1 file changed, 30 insertions(+), 19 deletions(-) diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index 7e10995adc..611e8b0354 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -1003,8 +1003,8 @@ static void do_write(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) } } -static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg, - struct fuse_bufvec *ibufv) +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; struct fuse_bufvec *pbufv = ibufv; @@ -1012,28 +1012,27 @@ 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)); + + arg = fuse_mbuf_iter_advance(iter, arg_size); + if (!arg) { + fuse_reply_err(req, EINVAL); + return; + } + + 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) { - 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 { /* @@ -1043,6 +1042,13 @@ 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); } @@ -2052,12 +2058,17 @@ void fuse_session_process_buf_int(struct fuse_session *se, 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, @@ -2129,7 +2140,7 @@ 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); }