From nobody Fri Dec 19 08:11:56 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1576171223; cv=none; d=zohomail.com; s=zohoarc; b=hFjC5iXYdOEaey3/JHHY9oLlK1laIC5u9D0np9QCNpqBk8Mnl6coqEr6XcENGgmHxY6VZnCWZmmSEDpxRBVal40kO7doYnqBcwVIaHJ3F+EpX0jyvXD7FPKBfBBkKD0ioVWMDgHsPWiNRk1yw0TyDC+MizkW/DHXLPnueWU8IZM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1576171223; h=Content-Type:Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=VjEwVaezMuip00LU8LWeyiaqeheyGFWg4hB1UkA3M9I=; b=aNGedG7slqYrjLnJOJ4YCQdnwnArS69I74U670lC8s6KySj48u4/1XFj5i6oNxM0JQbkuetjNiMWYCsk1uk/xrrgEiIn0ZD/26PLwHQsBplhDRRJyxMZlGzxR+BDT99iuKySopb6BIKk1Jz6GwjoZyKwA2XRIBdHG3VPBbqmEos= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 157617122357269.68805615606504; Thu, 12 Dec 2019 09:20:23 -0800 (PST) Received: from localhost ([::1]:34562 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifS8U-0008VR-10 for importer@patchew.org; Thu, 12 Dec 2019 12:20:22 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50811) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifRVk-0005v8-1q for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ifRVi-0002KB-P2 for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:19 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:39425 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 1ifRVi-0002JT-KE for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:18 -0500 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-67-lOfNfn8yP1O3Zdo1yZsXAg-1; Thu, 12 Dec 2019 11:40:16 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9B46F107ACC5 for ; Thu, 12 Dec 2019 16:40:15 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-226.ams2.redhat.com [10.36.116.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id C009760BE1; Thu, 12 Dec 2019 16:40:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576168818; 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=VjEwVaezMuip00LU8LWeyiaqeheyGFWg4hB1UkA3M9I=; b=cfRQAoKEn9TsifQfn7TsxFTK6P6nowJCWrrgucDi0hZNAYjp2tGleiOcHb3qoL7PmRCW3Q AHdO9lF1FDltPO9EpJliz/+4MCH9wdm7C9xjkiRFqQ5ZZQEE6DOxPByHYFRkkToj9pMdbi pJpQ8vtnBtTSKomJtIQVd+hQJESqAY4= From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com Subject: [PATCH 042/104] virtiofsd: validate input buffer sizes in do_write_buf() Date: Thu, 12 Dec 2019 16:38:02 +0000 Message-Id: <20191212163904.159893-43-dgilbert@redhat.com> In-Reply-To: <20191212163904.159893-1-dgilbert@redhat.com> References: <20191212163904.159893-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: lOfNfn8yP1O3Zdo1yZsXAg-1 X-Mimecast-Spam-Score: 0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" 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 --- 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_lowleve= l.c index 7d33bbf539..4b1777b991 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -1005,8 +1005,8 @@ static void do_write(fuse_req_t req, fuse_ino_t nodei= d, const void *inarg) } } =20 -static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *in= arg, - 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 =3D req->se; struct fuse_bufvec *pbufv =3D ibufv; @@ -1014,28 +1014,27 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t= nodeid, const void *inarg, .buf[0] =3D ibufv->buf[0], .count =3D 1, }; - struct fuse_write_in *arg =3D (struct fuse_write_in *)inarg; + struct fuse_write_in *arg; + size_t arg_size =3D sizeof(*arg); struct fuse_file_info fi; =20 memset(&fi, 0, sizeof(fi)); + + arg =3D fuse_mbuf_iter_advance(iter, arg_size); + if (!arg) { + fuse_reply_err(req, EINVAL); + return; + } + + fi.lock_owner =3D arg->lock_owner; + fi.flags =3D arg->flags; fi.fh =3D arg->fh; fi.writepage =3D arg->write_flags & FUSE_WRITE_CACHE; =20 if (ibufv->count =3D=3D 1) { - fi.lock_owner =3D arg->lock_owner; - fi.flags =3D arg->flags; - if (!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD)) { - tmpbufv.buf[0].mem =3D PARAM(arg); - } - tmpbufv.buf[0].size -=3D - 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 =3D arg->size; + assert(!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD)); + tmpbufv.buf[0].mem =3D ((char *)arg) + arg_size; + tmpbufv.buf[0].size -=3D sizeof(struct fuse_in_header) + arg_size; pbufv =3D &tmpbufv; } else { /* @@ -1045,6 +1044,13 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t = nodeid, const void *inarg, ibufv->buf[0].size =3D 0; } =20 + if (fuse_buf_size(pbufv) !=3D 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); } =20 @@ -2055,12 +2061,17 @@ void fuse_session_process_buf_int(struct fuse_sessi= on *se, struct fuse_chan *ch) { const struct fuse_buf *buf =3D bufv->buf; + struct fuse_mbuf_iter iter =3D FUSE_MBUF_ITER_INIT(buf); struct fuse_in_header *in; const void *inarg; struct fuse_req *req; int err; =20 - in =3D buf->mem; + /* The first buffer must be a memory buffer */ + assert(!(buf->flags & FUSE_BUF_IS_FD)); + + in =3D fuse_mbuf_iter_advance(&iter, sizeof(*in)); + assert(in); /* caller guarantees the input buffer is large enough */ =20 if (se->debug) { fuse_log(FUSE_LOG_DEBUG, @@ -2132,7 +2143,7 @@ void fuse_session_process_buf_int(struct fuse_session= *se, =20 inarg =3D (void *)&in[1]; if (in->opcode =3D=3D 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); } --=20 2.23.0