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 77220C433FE for ; Fri, 18 Nov 2022 10:03:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241306AbiKRKDE (ORCPT ); Fri, 18 Nov 2022 05:03:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234664AbiKRKDD (ORCPT ); Fri, 18 Nov 2022 05:03:03 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7B554C27E for ; Fri, 18 Nov 2022 02:02:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668765726; 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=d27Wd07UL1xgazgC6/XC+sjZnlNtWArqOEu0HeUIGO0=; b=M+u1zt+MGh55ssV/NAMq0MrgTYI7qu03ohGJqgL+Jo1P2reabT+qapXdhWx6/t7XguzgB1 c3ArNMaCA/FZ2tGIQJZ01axZCJX7DVawzu+E5mv/hl3mx6s0vshiUY2oOA4rdXvsPEihqA CZb9p62EKta264EUPEAKWu4n/wnlZVw= 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-298-0D3nuEEwOFm4gb71MPGE7A-1; Fri, 18 Nov 2022 05:02:04 -0500 X-MC-Unique: 0D3nuEEwOFm4gb71MPGE7A-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 26EB6800B23 for ; Fri, 18 Nov 2022 10:02:04 +0000 (UTC) Received: from localhost (ovpn-194-48.brq.redhat.com [10.40.194.48]) by smtp.corp.redhat.com (Postfix) with ESMTP id C82952166B29 for ; Fri, 18 Nov 2022 10:02:03 +0000 (UTC) From: Petr Lautrbach To: selinux@vger.kernel.org Subject: Re: [PATCH v2] fixfiles: Unmount temporary bind mounts on SIGINT In-Reply-To: <87leonc95h.fsf@redhat.com> References: <20221107092504.1088612-1-plautrba@redhat.com> <87leonc95h.fsf@redhat.com> Date: Fri, 18 Nov 2022 11:02:03 +0100 Message-ID: <87edu01sys.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: > 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 > Any objections? >> >> >> policycoreutils/scripts/fixfiles | 36 +++++++++++++++++++++++++------- >> 1 file changed, 28 insertions(+), 8 deletions(-) >> >> diff --git a/policycoreutils/scripts/fixfiles b/policycoreutils/scripts/= fixfiles >> 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 ${= FC} -r "${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 al= ready been >> # mounted over >> for m in `echo $FILESYSTEMSRW`; do >> - TMP_MOUNT=3D"$(mktemp -d)" >> - test -z ${TMP_MOUNT+x} && echo "Unable to find temporary d= irectory!" && exit 1 >> - >> - mkdir -p "${TMP_MOUNT}${m}" || exit 1 >> - mount --bind "${m}" "${TMP_MOUNT}${m}" || exit 1 >> - ${SETFILES} ${VERBOSE} ${EXCLUDEDIRS} ${FORCEFLAG} ${THREA= DS} $* -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 T= MP_MOUNT m >> + if type unshare &> /dev/null; then >> + unshare -m bash -c "fix_labels_on_mountpoint $*" || ex= it $? >> + else >> + trap umount_TMP_MOUNT EXIT >> + fix_labels_on_mountpoint $* >> + trap EXIT >> + fi >> done; >> fi >> else >> --=20 >> 2.37.3