From f2e0162846cbb84abf6fd9a38fabdfd588f4eb2f Mon Sep 17 00:00:00 2001 From: Colin Walters Date: Thu, 20 Feb 2014 18:25:56 -0500 Subject: [PATCH] upgrade: Refuse chronologically older commits unless --allow-downgrade We don't want to allow MITM attackers to intercept upgrade requests and provide clients with older OS versions vulnerable to security flaws. Only "ostree admin upgrade" gets this behavior for now - whether we want to do it for "ostree admin switch" is another question. --- Makefile-tests.am | 1 + src/libostree/ostree-core.c | 8 ++++ src/libostree/ostree-core.h | 1 + src/ostree/ot-admin-builtin-upgrade.c | 40 ++++++++++++++++ tests/libtest.sh | 11 +++++ tests/test-admin-upgrade-not-backwards.sh | 57 +++++++++++++++++++++++ 6 files changed, 118 insertions(+) create mode 100644 tests/test-admin-upgrade-not-backwards.sh diff --git a/Makefile-tests.am b/Makefile-tests.am index d1a8803d..13c5d60d 100644 --- a/Makefile-tests.am +++ b/Makefile-tests.am @@ -37,6 +37,7 @@ testfiles = test-basic \ test-admin-deploy-switch \ test-admin-deploy-etcmerge-cornercases \ test-admin-deploy-uboot \ + test-admin-upgrade-not-backwards \ test-setuid \ test-delta \ test-xattrs \ diff --git a/src/libostree/ostree-core.c b/src/libostree/ostree-core.c index 9b7a2379..b8fa114a 100644 --- a/src/libostree/ostree-core.c +++ b/src/libostree/ostree-core.c @@ -1755,3 +1755,11 @@ ostree_commit_get_parent (GVariant *commit_variant) return NULL; return ostree_checksum_from_bytes_v (bytes); } + +guint64 +ostree_commit_get_timestamp (GVariant *commit_variant) +{ + guint64 ret; + g_variant_get_child (commit_variant, 5, "t", &ret); + return GUINT64_FROM_BE (ret); +} diff --git a/src/libostree/ostree-core.h b/src/libostree/ostree-core.h index bd8e68fc..de1698d2 100644 --- a/src/libostree/ostree-core.h +++ b/src/libostree/ostree-core.h @@ -250,5 +250,6 @@ gboolean ostree_validate_structureof_dirmeta (GVariant *dirmeta, GError **error); gchar * ostree_commit_get_parent (GVariant *commit_variant); +guint64 ostree_commit_get_timestamp (GVariant *commit_variant); G_END_DECLS diff --git a/src/ostree/ot-admin-builtin-upgrade.c b/src/ostree/ot-admin-builtin-upgrade.c index 1b86cddc..9fcae678 100644 --- a/src/ostree/ot-admin-builtin-upgrade.c +++ b/src/ostree/ot-admin-builtin-upgrade.c @@ -34,11 +34,13 @@ #include static gboolean opt_reboot; +static gboolean opt_allow_downgrade; static char *opt_osname; static GOptionEntry options[] = { { "os", 0, 0, G_OPTION_ARG_STRING, &opt_osname, "Specify operating system root to use", NULL }, { "reboot", 'r', 0, G_OPTION_ARG_NONE, &opt_reboot, "Reboot after a successful upgrade", NULL }, + { "allow-downgrade", 0, 0, G_OPTION_ARG_NONE, &opt_allow_downgrade, "Permit deployment of chronologically older trees", NULL }, { NULL } }; @@ -109,6 +111,44 @@ ot_admin_builtin_upgrade (int argc, char **argv, OstreeSysroot *sysroot, GCancel else { gs_unref_object GFile *real_sysroot = g_file_new_for_path ("/"); + + if (!opt_allow_downgrade) + { + const char *old_revision = ostree_deployment_get_csum (merge_deployment); + gs_unref_variant GVariant *old_commit = NULL; + gs_unref_variant GVariant *new_commit = NULL; + + if (!ostree_repo_load_variant (repo, OSTREE_OBJECT_TYPE_COMMIT, + old_revision, + &old_commit, + error)) + goto out; + + if (!ostree_repo_load_variant (repo, OSTREE_OBJECT_TYPE_COMMIT, + new_revision, &new_commit, + error)) + goto out; + + if (ostree_commit_get_timestamp (old_commit) > ostree_commit_get_timestamp (new_commit)) + { + GDateTime *old_ts = g_date_time_new_from_unix_utc (ostree_commit_get_timestamp (old_commit)); + GDateTime *new_ts = g_date_time_new_from_unix_utc (ostree_commit_get_timestamp (new_commit)); + gs_free char *old_ts_str = NULL; + gs_free char *new_ts_str = NULL; + + g_assert (old_ts); + g_assert (new_ts); + old_ts_str = g_date_time_format (old_ts, "%c"); + new_ts_str = g_date_time_format (new_ts, "%c"); + g_date_time_unref (old_ts); + g_date_time_unref (new_ts); + + g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED, + "Upgrade target revision '%s' with timestamp '%s' is chronologically older than current revision '%s' with timestamp '%s'; use --allow-downgrade to permit", + new_revision, new_ts_str, old_revision, old_ts_str); + goto out; + } + } /* Here we perform cleanup of any leftover data from previous * partial failures. This avoids having to call gs_shutil_rm_rf() diff --git a/tests/libtest.sh b/tests/libtest.sh index da85c1c8..7d726a5c 100644 --- a/tests/libtest.sh +++ b/tests/libtest.sh @@ -223,6 +223,8 @@ EOF ostree --repo=${test_tmpdir}/testos-repo commit -b testos/buildmaster/x86_64-runtime -s "Build" + # Ensure these commits have distinct second timestamps + sleep 2 echo "a new executable" > usr/bin/sh ostree --repo=${test_tmpdir}/testos-repo commit -b testos/buildmaster/x86_64-runtime -s "Build" @@ -248,6 +250,15 @@ EOF setup_os_boot_uboot ;; esac + + cd ${test_tmpdir} + mkdir ${test_tmpdir}/httpd + cd httpd + ln -s ${test_tmpdir} ostree + ostree trivial-httpd --daemonize -p ${test_tmpdir}/httpd-port $args + port=$(cat ${test_tmpdir}/httpd-port) + echo "http://127.0.0.1:${port}" > ${test_tmpdir}/httpd-address + cd ${oldpwd} } os_repository_new_commit () diff --git a/tests/test-admin-upgrade-not-backwards.sh b/tests/test-admin-upgrade-not-backwards.sh new file mode 100644 index 00000000..6ea988b8 --- /dev/null +++ b/tests/test-admin-upgrade-not-backwards.sh @@ -0,0 +1,57 @@ +#!/bin/bash +# +# Copyright (C) 2014 Colin Walters +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2 of the License, or (at your option) any later version. +# +# This library is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, write to the +# Free Software Foundation, Inc., 59 Temple Place - Suite 330, +# Boston, MA 02111-1307, USA. + +set -e + +. $(dirname $0)/libtest.sh + +echo "1..1" + +setup_os_repository "archive-z2" "syslinux" + +echo "ok setup" + +echo "1..2" + +cd ${test_tmpdir} +ostree --repo=sysroot/ostree/repo remote add --set=gpg-verify=false testos $(cat httpd-address)/ostree/testos-repo +ostree --repo=sysroot/ostree/repo pull testos testos/buildmaster/x86_64-runtime +rev=$(ostree --repo=sysroot/ostree/repo rev-parse testos/buildmaster/x86_64-runtime) +export rev +echo "rev=${rev}" +# This initial deployment gets kicked off with some kernel arguments +ostree admin --sysroot=sysroot deploy --karg=root=LABEL=MOO --karg=quiet --os=testos testos:testos/buildmaster/x86_64-runtime +assert_has_dir sysroot/boot/ostree/testos-${bootcsum} + +# This should be a no-op +ostree admin --sysroot=sysroot upgrade --os=testos + +# Now reset to an older revision +ostree --repo=${test_tmpdir}/testos-repo reset testos/buildmaster/x86_64-runtime{,^} + +if ostree admin --sysroot=sysroot upgrade --os=testos 2>upgrade-err.txt; then + assert_not_reached 'upgrade unexpectedly succeeded' +fi +assert_file_has_content upgrade-err.txt 'chronologically older' + +echo 'ok upgrade will not go backwards' + +ostree admin --sysroot=sysroot upgrade --os=testos --allow-downgrade + +echo 'ok upgrade backwards'