From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 9B191C433DB for ; Fri, 12 Mar 2021 14:37:48 +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 2D84964F59 for ; Fri, 12 Mar 2021 14:37:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D84964F59 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55162 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lKivB-000372-IL for qemu-devel@archiver.kernel.org; Fri, 12 Mar 2021 09:37:45 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:48148) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lKiUh-0002ge-TW for qemu-devel@nongnu.org; Fri, 12 Mar 2021 09:10:23 -0500 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:46968) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lKiUf-0003uV-H4 for qemu-devel@nongnu.org; Fri, 12 Mar 2021 09:10:23 -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-150-MO7gm_TUOemda3JyKN8QPA-1; Fri, 12 Mar 2021 09:10:16 -0500 X-MC-Unique: MO7gm_TUOemda3JyKN8QPA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CB2C4107ACCA; Fri, 12 Mar 2021 14:10:15 +0000 (UTC) Received: from bahia.redhat.com (ovpn-113-236.ams2.redhat.com [10.36.113.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 765DA5D6D7; Fri, 12 Mar 2021 14:10:14 +0000 (UTC) From: Greg Kurz To: qemu-devel@nongnu.org Subject: [PATCH 1/3] virtiofsd: Don't allow empty paths in lookup_name() Date: Fri, 12 Mar 2021 15:10:01 +0100 Message-Id: <20210312141003.819108-2-groug@kaod.org> In-Reply-To: <20210312141003.819108-1-groug@kaod.org> References: <20210312141003.819108-1-groug@kaod.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kaod.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=WINDOWS-1252 Received-SPF: softfail client-ip=205.139.111.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665 autolearn=no autolearn_force=no X-Spam_action: no action 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: , Cc: virtio-fs@redhat.com, Miklos Szeredi , "Dr. David Alan Gilbert" , Stefan Hajnoczi , Greg Kurz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" When passed an empty filename, lookup_name() returns the inode of the parent directory, unless the parent is the root in which case the st_dev doesn't match and lo_find() returns NULL. This is because lookup_name() passes AT_EMPTY_PATH down to fstatat() or statx(). This behavior doesn't quite make sense because users of lookup_name() then pass the name to unlinkat(), renameat() or renameat2(), all of which will always fail on empty names. Drop AT_EMPTY_PATH from the flags in lookup_name() so that it has the consistent behavior of "returning an existing child inode or NULL" for all directories. Signed-off-by: Greg Kurz --- tools/virtiofsd/passthrough_ll.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough= _ll.c index fc7e1b1e8e2b..27a6c636dcaf 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -1308,8 +1308,7 @@ static struct lo_inode *lookup_name(fuse_req_t req, f= use_ino_t parent, return NULL; } =20 - res =3D do_statx(lo, dir->fd, name, &attr, - AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW, &mnt_id); + res =3D do_statx(lo, dir->fd, name, &attr, AT_SYMLINK_NOFOLLOW, &mnt_i= d); lo_inode_put(lo, &dir); if (res =3D=3D -1) { return NULL; --=20 2.26.2