user units: implicitly enable PrivateUsers= when sandboxing options a…

…re set

Enabling these options when not running as root requires a user
namespace, so implicitly enable PrivateUsers=.
This has a side effect as it changes which users are visible to the unit.
However until now these options did not work at all for user units, and
in practice just a handful of user units in Fedora, Debian and Ubuntu
mistakenly used them (and they have been all fixed since).

This fixes the long-standing confusing issue that the user and system
units take the same options but the behaviour is wildly (and sometimes
silently) different depending on which is which, with user units
requiring manually specifiying PrivateUsers= in order for sandboxing
options to actually work and not be silently ignored.

man/system-or-user-ns.xml

@@ -8,9 +8,13 @@
 <refsect1>
 
 <para id="singular">This option is only available for system services, or for services running in per-user
- instances of the service manager when <varname>PrivateUsers=</varname> is enabled.</para>
+ instances of the service manager in which case <varname>PrivateUsers=</varname> is implicitly enabled
+ (requires unprivileged user namespaces support to be enabled in the kernel via the
+ <literal>kernel.unprivileged_userns_clone=</literal> sysctl).</para>
 
 <para id="plural">These options are only available for system services, or for services running in per-user
- instances of the service manager when <varname>PrivateUsers=</varname> is enabled.</para>
+ instances of the service manager in which case <varname>PrivateUsers=</varname> is implicitly enabled
+ (requires unprivileged user namespaces support to be enabled in the kernel via the
+ <literal>kernel.unprivileged_userns_clone=</literal> sysctl).</para>
 
 </refsect1>

src/core/execute.c

@@ -4400,6 +4400,44 @@ static void log_command_line(Unit *unit, const char *msg, const char *executable
                         LOG_UNIT_INVOCATION_ID(unit));
 }
 
+static bool exec_context_need_unprivileged_private_users(const ExecContext *context, const Manager *manager) {
+        assert(context);
+        assert(manager);
+
+        /* These options require PrivateUsers= when used in user units, as we need to be in a user namespace
+         * to have permission to enable them when not running as root. If we have effective CAP_SYS_ADMIN
+         * (system manager) then we have privileges and don't need this. */
+        if (MANAGER_IS_SYSTEM(manager))
+                return false;
+
+        return context->private_users ||
+               context->private_tmp ||
+               context->private_devices ||
+               context->private_network ||
+               context->network_namespace_path ||
+               context->private_ipc ||
+               context->ipc_namespace_path ||
+               context->private_mounts ||
+               context->mount_apivfs ||
+               context->n_bind_mounts > 0 ||
+               context->n_temporary_filesystems > 0 ||
+               context->root_directory ||
+               !strv_isempty(context->extension_directories) ||
+               context->protect_system != PROTECT_SYSTEM_NO ||
+               context->protect_home != PROTECT_HOME_NO ||
+               context->protect_kernel_tunables ||
+               context->protect_kernel_modules ||
+               context->protect_kernel_logs ||
+               context->protect_control_groups ||
+               context->protect_clock ||
+               context->protect_hostname ||
+               !strv_isempty(context->read_write_paths) ||
+               !strv_isempty(context->read_only_paths) ||
+               !strv_isempty(context->inaccessible_paths) ||
+               !strv_isempty(context->exec_paths) ||
+               !strv_isempty(context->no_exec_paths);
+}
+
 static int exec_child(
                 Unit *unit,
                 const ExecCommand *command,
@@ -5032,17 +5070,22 @@ static int exec_child(
                 }
         }
 
-        if (needs_sandboxing && context->private_users && have_effective_cap(CAP_SYS_ADMIN) <= 0) {
+        if (needs_sandboxing && exec_context_need_unprivileged_private_users(context, unit->manager)) {
                 /* If we're unprivileged, set up the user namespace first to enable use of the other namespaces.
                  * Users with CAP_SYS_ADMIN can set up user namespaces last because they will be able to
                  * set up the all of the other namespaces (i.e. network, mount, UTS) without a user namespace. */
 
-                userns_set_up = true;
                 r = setup_private_users(saved_uid, saved_gid, uid, gid);
-                if (r < 0) {
+                /* If it was requested explicitly and we can't set it up, fail early. Otherwise, continue and let
+                 * the actual requested operations fail (or silently continue). */
+                if (r < 0 && context->private_users) {
                         *exit_status = EXIT_USER;
                         return log_unit_error_errno(unit, r, "Failed to set up user namespacing for unprivileged user: %m");
                 }
+                if (r < 0)
+                        log_unit_info_errno(unit, r, "Failed to set up user namespacing for unprivileged user, ignoring: %m");
+                else
+                        userns_set_up = true;
         }
 
         if (exec_needs_network_namespace(context) && runtime && runtime->shared && runtime->shared->netns_storage_socket[0] >= 0) {

src/test/test-execute.c

@@ -401,9 +401,9 @@ static void test_exec_ignoresigpipe(Manager *m) {
 static void test_exec_privatetmp(Manager *m) {
         assert_se(touch("/tmp/test-exec_privatetmp") >= 0);
 
-        test(m, "exec-privatetmp-yes.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-privatetmp-yes.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
         test(m, "exec-privatetmp-no.service", 0, CLD_EXITED);
-        test(m, "exec-privatetmp-disabled-by-prefix.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-privatetmp-disabled-by-prefix.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 
         unlink("/tmp/test-exec_privatetmp");
 }
@@ -420,10 +420,10 @@ static void test_exec_privatedevices(Manager *m) {
                 return;
         }
 
-        test(m, "exec-privatedevices-yes.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-privatedevices-yes.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
         test(m, "exec-privatedevices-no.service", 0, CLD_EXITED);
-        test(m, "exec-privatedevices-disabled-by-prefix.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
-        test(m, "exec-privatedevices-yes-with-group.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_GROUP, CLD_EXITED);
+        test(m, "exec-privatedevices-disabled-by-prefix.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
+        test(m, "exec-privatedevices-yes-with-group.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 
         /* We use capsh to test if the capabilities are
          * properly set, so be sure that it exists */
@@ -433,10 +433,10 @@ static void test_exec_privatedevices(Manager *m) {
                 return;
         }
 
-        test(m, "exec-privatedevices-yes-capability-mknod.service", 0, CLD_EXITED);
-        test(m, "exec-privatedevices-no-capability-mknod.service", MANAGER_IS_SYSTEM(m) ? 0 : EXIT_FAILURE, CLD_EXITED);
-        test(m, "exec-privatedevices-yes-capability-sys-rawio.service", 0, CLD_EXITED);
-        test(m, "exec-privatedevices-no-capability-sys-rawio.service", MANAGER_IS_SYSTEM(m) ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-privatedevices-yes-capability-mknod.service", can_unshare || MANAGER_IS_SYSTEM(m) ? 0 : EXIT_NAMESPACE, CLD_EXITED);
+        test(m, "exec-privatedevices-no-capability-mknod.service", 0, CLD_EXITED);
+        test(m, "exec-privatedevices-yes-capability-sys-rawio.service", MANAGER_IS_SYSTEM(m) ? 0 : EXIT_NAMESPACE, CLD_EXITED);
+        test(m, "exec-privatedevices-no-capability-sys-rawio.service", 0, CLD_EXITED);
 }
 
 static void test_exec_protecthome(Manager *m) {
@@ -466,23 +466,23 @@ static void test_exec_protectkernelmodules(Manager *m) {
                 return;
         }
 
-        test(m, "exec-protectkernelmodules-no-capabilities.service", MANAGER_IS_SYSTEM(m) ? 0 : EXIT_FAILURE, CLD_EXITED);
-        test(m, "exec-protectkernelmodules-yes-capabilities.service", 0, CLD_EXITED);
-        test(m, "exec-protectkernelmodules-yes-mount-propagation.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-protectkernelmodules-no-capabilities.service", 0, CLD_EXITED);
+        test(m, "exec-protectkernelmodules-yes-capabilities.service", MANAGER_IS_SYSTEM(m) ? 0 : EXIT_NAMESPACE, CLD_EXITED);
+        test(m, "exec-protectkernelmodules-yes-mount-propagation.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_readonlypaths(Manager *m) {
 
-        test(m, "exec-readonlypaths-simple.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-readonlypaths-simple.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 
         if (path_is_read_only_fs("/var") > 0) {
                 log_notice("Directory /var is readonly, skipping remaining tests in %s", __func__);
                 return;
         }
 
-        test(m, "exec-readonlypaths.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-readonlypaths.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
         test(m, "exec-readonlypaths-with-bindpaths.service", can_unshare ? 0 : EXIT_NAMESPACE, CLD_EXITED);
-        test(m, "exec-readonlypaths-mount-propagation.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-readonlypaths-mount-propagation.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_readwritepaths(Manager *m) {
@@ -492,7 +492,7 @@ static void test_exec_readwritepaths(Manager *m) {
                 return;
         }
 
-        test(m, "exec-readwritepaths-mount-propagation.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-readwritepaths-mount-propagation.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_inaccessiblepaths(Manager *m) {
@@ -502,14 +502,14 @@ static void test_exec_inaccessiblepaths(Manager *m) {
                 return;
         }
 
-        test(m, "exec-inaccessiblepaths-sys.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-inaccessiblepaths-sys.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 
         if (path_is_read_only_fs("/") > 0) {
                 log_notice("Root directory is readonly, skipping remaining tests in %s", __func__);
                 return;
         }
 
-        test(m, "exec-inaccessiblepaths-mount-propagation.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-inaccessiblepaths-mount-propagation.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static int on_spawn_io(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
@@ -687,14 +687,14 @@ static void test_exec_mount_apivfs(Manager *m) {
 
         assert_se(mkdir_p("/tmp/test-exec-mount-apivfs-no/root", 0755) >= 0);
 
-        test(m, "exec-mount-apivfs-no.service", can_unshare ? 0 : EXIT_NAMESPACE, CLD_EXITED);
+        test(m, "exec-mount-apivfs-no.service", can_unshare || !MANAGER_IS_SYSTEM(m) ? 0 : EXIT_NAMESPACE, CLD_EXITED);
 
         (void) rm_rf("/tmp/test-exec-mount-apivfs-no/root", REMOVE_ROOT|REMOVE_PHYSICAL);
 }
 
 static void test_exec_noexecpaths(Manager *m) {
 
-        test(m, "exec-noexecpaths-simple.service", can_unshare ? 0 : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-noexecpaths-simple.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_temporaryfilesystem(Manager *m) {
@@ -964,8 +964,8 @@ static void test_exec_passenvironment(Manager *m) {
 }
 
 static void test_exec_umask(Manager *m) {
-        test(m, "exec-umask-default.service", 0, CLD_EXITED);
-        test(m, "exec-umask-0177.service", 0, CLD_EXITED);
+        test(m, "exec-umask-default.service", can_unshare || MANAGER_IS_SYSTEM(m) ? 0 : EXIT_NAMESPACE, CLD_EXITED);
+        test(m, "exec-umask-0177.service", can_unshare || MANAGER_IS_SYSTEM(m) ? 0 : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_runtimedirectory(Manager *m) {
@@ -1012,7 +1012,7 @@ static void test_exec_capabilityboundingset(Manager *m) {
 }
 
 static void test_exec_basic(Manager *m) {
-        test(m, "exec-basic.service", 0, CLD_EXITED);
+        test(m, "exec-basic.service", can_unshare || MANAGER_IS_SYSTEM(m) ? 0 : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_ambientcapabilities(Manager *m) {
@@ -1052,17 +1052,16 @@ static void test_exec_ambientcapabilities(Manager *m) {
 }
 
 static void test_exec_privatenetwork(Manager *m) {
-        int r, status;
+        int r;
 
         r = find_executable("ip", NULL);
         if (r < 0) {
                 log_notice_errno(r, "Skipping %s, could not find ip binary: %m", __func__);
                 return;
         }
 
-        status = can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_NETWORK : EXIT_FAILURE;
-        test(m, "exec-privatenetwork-yes-privatemounts-no.service", status, CLD_EXITED);
-        test(m, "exec-privatenetwork-yes-privatemounts-yes.service", status, CLD_EXITED);
+        test(m, "exec-privatenetwork-yes-privatemounts-no.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_NETWORK : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-privatenetwork-yes-privatemounts-yes.service", can_unshare ? 0 : MANAGER_IS_SYSTEM(m) ? EXIT_NETWORK : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_networknamespacepath(Manager *m) {
@@ -1075,7 +1074,7 @@ static void test_exec_networknamespacepath(Manager *m) {
         }
 
         test(m, "exec-networknamespacepath-privatemounts-no.service", MANAGER_IS_SYSTEM(m) ? EXIT_SUCCESS : EXIT_FAILURE, CLD_EXITED);
-        test(m, "exec-networknamespacepath-privatemounts-yes.service", can_unshare ? EXIT_SUCCESS : EXIT_FAILURE, CLD_EXITED);
+        test(m, "exec-networknamespacepath-privatemounts-yes.service", can_unshare ? EXIT_SUCCESS : MANAGER_IS_SYSTEM(m) ? EXIT_FAILURE : EXIT_NAMESPACE, CLD_EXITED);
 }
 
 static void test_exec_oomscoreadjust(Manager *m) {
@@ -1105,12 +1104,12 @@ static void test_exec_unsetenvironment(Manager *m) {
 }
 
 static void test_exec_specifier(Manager *m) {
-        test(m, "exec-specifier.service", 0, CLD_EXITED);
+        test(m, "exec-specifier.service", can_unshare || MANAGER_IS_SYSTEM(m) ? 0 : EXIT_FAILURE, CLD_EXITED);
         if (MANAGER_IS_SYSTEM(m))
                 test(m, "exec-specifier-system.service", 0, CLD_EXITED);
         else
                 test(m, "exec-specifier-user.service", 0, CLD_EXITED);
-        test(m, "exec-specifier@foo-bar.service", 0, CLD_EXITED);
+        test(m, "exec-specifier@foo-bar.service", can_unshare || MANAGER_IS_SYSTEM(m) ? 0 : EXIT_FAILURE, CLD_EXITED);
         test(m, "exec-specifier-interpolation.service", 0, CLD_EXITED);
 }
 

test/units/testsuite-43.sh

@@ -17,15 +17,15 @@ runas testuser systemd-run --wait --user --unit=test-private-users \
 runas testuser systemctl --user log-level debug
 
 runas testuser systemd-run --wait --user --unit=test-private-tmp-innerfile \
-    -p PrivateUsers=yes -p PrivateTmp=yes \
+    -p PrivateTmp=yes \
     -P touch /tmp/innerfile.txt
 # File should not exist outside the job's tmp directory.
 test ! -e /tmp/innerfile.txt
 
 touch /tmp/outerfile.txt
 # File should not appear in unit's private tmp.
 runas testuser systemd-run --wait --user --unit=test-private-tmp-outerfile \
-    -p PrivateUsers=yes -p PrivateTmp=yes \
+    -p PrivateTmp=yes \
     -P test ! -e /tmp/outerfile.txt
 
 # Confirm that creating a file in home works
@@ -35,7 +35,7 @@ test -e /home/testuser/works.txt
 
 # Confirm that creating a file in home is blocked under read-only
 runas testuser systemd-run --wait --user --unit=test-protect-home-read-only \
-    -p PrivateUsers=yes -p ProtectHome=read-only \
+    -p ProtectHome=read-only \
     -P bash -c '
         test -e /home/testuser/works.txt || exit 10
         touch /home/testuser/blocked.txt && exit 11
@@ -45,13 +45,13 @@ test ! -e /home/testuser/blocked.txt
 
 # Check that tmpfs hides the whole directory
 runas testuser systemd-run --wait --user --unit=test-protect-home-tmpfs \
-    -p PrivateUsers=yes -p ProtectHome=tmpfs \
+    -p ProtectHome=tmpfs \
     -P test ! -e /home/testuser
 
 # Confirm that home, /root, and /run/user are inaccessible under "yes"
 # shellcheck disable=SC2016
 runas testuser systemd-run --wait --user --unit=test-protect-home-yes \
-    -p PrivateUsers=yes -p ProtectHome=yes \
+    -p ProtectHome=yes \
     -P bash -c '
         test "$(stat -c %a /home)" = "0"
         test "$(stat -c %a /root)" = "0"
@@ -70,11 +70,11 @@ runas testuser systemd-run --wait --user --unit=test-group-fail \
 # Check that with a new user namespace we can bind mount
 # files and use a different root directory
 runas testuser systemd-run --wait --user --unit=test-bind-mount \
-    -p PrivateUsers=yes -p BindPaths=/dev/null:/etc/os-release \
+    -p BindPaths=/dev/null:/etc/os-release \
     test ! -s /etc/os-release
 
 runas testuser systemd-run --wait --user --unit=test-read-write \
-    -p PrivateUsers=yes -p ReadOnlyPaths=/ \
+    -p ReadOnlyPaths=/ \
     -p ReadWritePaths="/var /run /tmp" \
     -p NoExecPaths=/ -p ExecPaths=/usr \
     test ! -w /etc/os-release
@@ -85,50 +85,50 @@ runas testuser systemd-run --wait --user --unit=test-caps \
     test -s /etc/os-release
 
 runas testuser systemd-run --wait --user --unit=test-devices \
-    -p PrivateUsers=yes -p PrivateDevices=yes -p PrivateIPC=yes \
+    -p PrivateDevices=yes -p PrivateIPC=yes \
     sh -c "ls -1 /dev/ | wc -l | grep -q -F 18"
 
 # Same check as test/test-execute/exec-privatenetwork-yes.service
 runas testuser systemd-run --wait --user --unit=test-network \
-    -p PrivateUsers=yes -p PrivateNetwork=yes \
+    -p PrivateNetwork=yes \
     /bin/sh -x -c '! ip link | grep -E "^[0-9]+: " | grep -Ev ": (lo|(erspan|gre|gretap|ip_vti|ip6_vti|ip6gre|ip6tnl|sit|tunl)0@.*):"'
 
 runas testuser systemd-run --wait --user --unit=test-hostname \
-    -p PrivateUsers=yes -p ProtectHostname=yes \
+    -p ProtectHostname=yes \
     hostnamectl hostname foo \
     && { echo 'unexpected success'; exit 1; }
 
 runas testuser systemd-run --wait --user --unit=test-clock \
-    -p PrivateUsers=yes -p ProtectClock=yes \
+    -p ProtectClock=yes \
     timedatectl set-time "2012-10-30 18:17:16" \
     && { echo 'unexpected success'; exit 1; }
 
 runas testuser systemd-run --wait --user --unit=test-kernel-tunable \
-    -p PrivateUsers=yes -p ProtectKernelTunables=yes \
+    -p ProtectKernelTunables=yes \
     sh -c "echo 0 >/proc/sys/user/max_user_namespaces" \
     && { echo 'unexpected success'; exit 1; }
 
 runas testuser systemd-run --wait --user --unit=test-kernel-mod \
-    -p PrivateUsers=yes -p ProtectKernelModules=yes \
+    -p ProtectKernelModules=yes \
     sh -c "modprobe -r overlay && modprobe overlay" \
     && { echo 'unexpected success'; exit 1; }
 
 if sysctl kernel.dmesg_restrict=0; then
     runas testuser systemd-run --wait --user --unit=test-kernel-log \
-        -p PrivateUsers=yes -p ProtectKernelLogs=yes -p LogNamespace=yes \
+        -p ProtectKernelLogs=yes -p LogNamespace=yes \
         dmesg \
         && { echo 'unexpected success'; exit 1; }
 fi
 
 unsquashfs -no-xattrs -d /tmp/img /usr/share/minimal_0.raw
 runas testuser systemd-run --wait --user --unit=test-root-dir \
-    -p PrivateUsers=yes -p RootDirectory=/tmp/img \
+    -p RootDirectory=/tmp/img \
     grep MARKER=1 /etc/os-release
 
 mkdir /tmp/img_bind
 mount --bind /tmp/img /tmp/img_bind
 runas testuser systemd-run --wait --user --unit=test-root-dir-bind \
-    -p PrivateUsers=yes -p RootDirectory=/tmp/img_bind -p MountFlags=private \
+    -p RootDirectory=/tmp/img_bind -p MountFlags=private \
     grep MARKER=1 /etc/os-release
 umount /tmp/img_bind
 
@@ -137,7 +137,7 @@ mkdir -p /tmp/a /tmp/b /tmp/c
 if unshare --mount --user --map-root-user mount -t overlay overlay /tmp/c -o lowerdir=/tmp/a:/tmp/b; then
     unsquashfs -no-xattrs -d /tmp/app2 /usr/share/app1.raw
     runas testuser systemd-run --wait --user --unit=test-extension-dir \
-        -p PrivateUsers=yes -p ExtensionDirectories=/tmp/app2 \
+        -p ExtensionDirectories=/tmp/app2 \
         -p TemporaryFileSystem=/run -p RootDirectory=/tmp/img \
         -p MountAPIVFS=yes \
         grep PORTABLE_PREFIXES=app1 /usr/lib/extension-release.d/extension-release.app2