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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDF03C4332F for ; Mon, 7 Nov 2022 11:11:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231577AbiKGLLu (ORCPT ); Mon, 7 Nov 2022 06:11:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231888AbiKGLLi (ORCPT ); Mon, 7 Nov 2022 06:11:38 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2825CF5 for ; Mon, 7 Nov 2022 03:10:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667819437; 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=xKObO2xkXBLOedp4GFNWRraEd9f36b5PNZhV6f12p+I=; b=bO999Nq9ajiXprg4uLHLbjlNyYZJIjfgbXQwS5qNwp0rQHbLH1f6j8qheEY3AehEd/SHXK Dxr2nfjawnDLEjNY4x1alFF6gM0u6Udlg6gnHIOt6vu4jSmiu0Z5SrzEMXRFwTXp8ZjixR /p1M3LU0QdoBwdALUmH2jbhavMY0h6U= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-133-CALlWQbuPaK2KkkqJDqw5A-1; Mon, 07 Nov 2022 06:10:36 -0500 X-MC-Unique: CALlWQbuPaK2KkkqJDqw5A-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C588585A583 for ; Mon, 7 Nov 2022 11:10:35 +0000 (UTC) Received: from localhost (ovpn-192-172.brq.redhat.com [10.40.192.172]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7CA162166B29 for ; Mon, 7 Nov 2022 11:10:35 +0000 (UTC) From: Petr Lautrbach To: selinux@vger.kernel.org Subject: Re: [PATCH v2] fixfiles: Unmount temporary bind mounts on SIGINT In-Reply-To: <20221107092504.1088612-1-plautrba@redhat.com> References: <20221107092504.1088612-1-plautrba@redhat.com> Date: Mon, 07 Nov 2022 12:10:34 +0100 Message-ID: <87leonc95h.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Petr Lautrbach writes: > `fixfiles -M relabel` temporary bind mounts file systems before > relabeling, but it left the / directory mounted in /tmp/tmp.XXXX when a > user hit CTRL-C. It means that if the user run `fixfiles -M relabel` > again and answered Y to clean out /tmp directory, it would remove all > data from mounted fs. > > This patch changes the location where `fixfiles` mounts fs to /run, uses > private mount namespace via unshare and adds a handler for exit signals > which tries to umount fs mounted by `fixfiles`. > > Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=3D2125355 > > Signed-off-by: Petr Lautrbach > --- Actually, it's v5: v2: - set trap on EXIT instead of SIGINT v3: - use /run instead of /tmp for mountpoints v4: - use mount namespace as suggested by Christian G=C3=B6ttsche v5 - fixed issues reported by Christian G=C3=B6ttsche > > > policycoreutils/scripts/fixfiles | 36 +++++++++++++++++++++++++------- > 1 file changed, 28 insertions(+), 8 deletions(-) > > diff --git a/policycoreutils/scripts/fixfiles b/policycoreutils/scripts/f= ixfiles > index c72ca0eb9d61..166af6f360a2 100755 > --- a/policycoreutils/scripts/fixfiles > +++ b/policycoreutils/scripts/fixfiles > @@ -207,6 +207,25 @@ rpm -q --qf '[%{FILESTATES} %{FILENAMES}\n]' "$1" | = grep '^0 ' | cut -f2- -d ' ' > [ ${PIPESTATUS[0]} !=3D 0 ] && echo "$1 not found" >/dev/stderr > } >=20=20 > +# unmount tmp bind mount before exit > +umount_TMP_MOUNT() { > + if [ -n "$TMP_MOUNT" ]; then > + umount "${TMP_MOUNT}${m}" || exit 130 > + rm -rf "${TMP_MOUNT}" || echo "Error cleaning up." > + fi > + exit 130 > +} > + > +fix_labels_on_mountpoint() { > + test -z ${TMP_MOUNT+x} && echo "Unable to find temporary directory!" &&= exit 1 > + mkdir -p "${TMP_MOUNT}${m}" || exit 1 > + mount --bind "${m}" "${TMP_MOUNT}${m}" || exit 1 > + ${SETFILES} ${VERBOSE} ${EXCLUDEDIRS} ${FORCEFLAG} ${THREADS} $* -q ${F= C} -r "${TMP_MOUNT}" "${TMP_MOUNT}${m}" > + umount "${TMP_MOUNT}${m}" || exit 1 > + rm -rf "${TMP_MOUNT}" || echo "Error cleaning up." > +} > +export -f fix_labels_on_mountpoint > + > # > # restore > # if called with -n will only check file context > @@ -252,14 +271,15 @@ case "$RESTORE_MODE" in > # we bind mount so we can fix the labels of files that have alr= eady been > # mounted over > for m in `echo $FILESYSTEMSRW`; do > - TMP_MOUNT=3D"$(mktemp -d)" > - test -z ${TMP_MOUNT+x} && echo "Unable to find temporary di= rectory!" && exit 1 > - > - mkdir -p "${TMP_MOUNT}${m}" || exit 1 > - mount --bind "${m}" "${TMP_MOUNT}${m}" || exit 1 > - ${SETFILES} ${VERBOSE} ${EXCLUDEDIRS} ${FORCEFLAG} ${THREAD= S} $* -q ${FC} -r "${TMP_MOUNT}" "${TMP_MOUNT}${m}" > - umount "${TMP_MOUNT}${m}" || exit 1 > - rm -rf "${TMP_MOUNT}" || echo "Error cleaning up." > + TMP_MOUNT=3D"$(mktemp -p /run -d fixfiles.XXXXXXXXXX)" > + export SETFILES VERBOSE EXCLUDEDIRS FORCEFLAG THREADS FC TM= P_MOUNT m > + if type unshare &> /dev/null; then > + unshare -m bash -c "fix_labels_on_mountpoint $*" || exi= t $? > + else > + trap umount_TMP_MOUNT EXIT > + fix_labels_on_mountpoint $* > + trap EXIT > + fi > done; > fi > else > --=20 > 2.37.3