systemd/test/test-systemd-tmpfiles.py
Daniel P. Berrangé 8473ece90e test-systemd-tmpfiles: skip when /tmp has unexpected ownership
The systemd-tmpfiles binary will report a fatal error if /tmp is not owned
either by root, or by the current user:

  Detected unsafe path transition /tmp (owned by nobody) →
    /tmp/test-systemd-tmpfiles.a8qc6n18 (owned by berrange)
    during canonicalization of
    tmp/test-systemd-tmpfiles.a8qc6n18/test-content.7chd7rdi

When doing development inside a 'toolbox' container (which is required
on a Fedora SilverBlue distro), /tmp is owned by 'nobody', because it
has been passed through from the host and host UID 0 gets mapped to
UID 65536 by usernamespaces. This triggers the unsafe path transition
error message.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2023-10-26 14:46:15 +01:00

250 lines
9.1 KiB
Python
Executable File

#!/usr/bin/env python3
# SPDX-License-Identifier: LGPL-2.1-or-later
#
# systemd 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 2.1 of the License, or
# (at your option) any later version.
import os
import sys
import socket
import subprocess
import tempfile
import pwd
import grp
from pathlib import Path
try:
from systemd import id128
except ImportError:
id128 = None
EX_DATAERR = 65 # from sysexits.h
EXIT_TEST_SKIP = 77
try:
subprocess.run
except AttributeError:
sys.exit(EXIT_TEST_SKIP)
exe_with_args = sys.argv[1:]
temp_dir = tempfile.TemporaryDirectory(prefix='test-systemd-tmpfiles.')
# If /tmp isn't owned by either 'root' or the current user
# systemd-tmpfiles will exit with "Detected unsafe path transition"
# breaking this test
tmpowner = os.stat("/tmp").st_uid
if tmpowner != 0 and tmpowner != os.getuid():
print("Skip: /tmp is not owned by 'root' or current user")
sys.exit(EXIT_TEST_SKIP)
def test_line(line, *, user, returncode=EX_DATAERR, extra={}):
args = ['--user'] if user else []
print('Running {} on {!r}'.format(' '.join(exe_with_args + args), line))
c = subprocess.run(exe_with_args + ['--create', '-'] + args,
input=line, stdout=subprocess.PIPE, universal_newlines=True,
**extra)
assert c.returncode == returncode, c
def test_invalids(*, user):
test_line('asdfa', user=user)
test_line('f "open quote', user=user)
test_line('f closed quote""', user=user)
test_line('Y /unknown/letter', user=user)
test_line('w non/absolute/path', user=user)
test_line('s', user=user) # s is for short
test_line('f!! /too/many/bangs', user=user)
test_line('f++ /too/many/plusses', user=user)
test_line('f+!+ /too/many/plusses', user=user)
test_line('f!+! /too/many/bangs', user=user)
test_line('f== /too/many/equals', user=user)
test_line('w /unresolved/argument - - - - "%Y"', user=user)
test_line('w /unresolved/argument/sandwich - - - - "%v%Y%v"', user=user)
test_line('w /unresolved/filename/%Y - - - - "whatever"', user=user)
test_line('w /unresolved/filename/sandwich/%v%Y%v - - - - "whatever"', user=user)
test_line('w - - - - - "no file specified"', user=user)
test_line('C - - - - - "no file specified"', user=user)
test_line('C non/absolute/path - - - - -', user=user)
test_line('b - - - - - -', user=user)
test_line('b 1234 - - - - -', user=user)
test_line('c - - - - - -', user=user)
test_line('c 1234 - - - - -', user=user)
test_line('t - - -', user=user)
test_line('T - - -', user=user)
test_line('a - - -', user=user)
test_line('A - - -', user=user)
test_line('h - - -', user=user)
test_line('H - - -', user=user)
def test_uninitialized_t():
if os.getuid() == 0:
return
test_line('w /foo - - - - "specifier for --user %t"',
user=True, returncode=0, extra={'env':{'HOME': os.getenv('HOME')}})
def test_content(line, expected, *, user, extra={}, subpath='/arg', path_cb=None):
d = tempfile.TemporaryDirectory(prefix='test-content.', dir=temp_dir.name)
if path_cb is not None:
path_cb(d.name, subpath)
arg = d.name + subpath
spec = line.format(arg)
test_line(spec, user=user, returncode=0, extra=extra)
content = open(arg).read()
print('expect: {!r}\nactual: {!r}'.format(expected, content))
assert content == expected
def test_valid_specifiers(*, user):
test_content('f {} - - - - two words', 'two words', user=user)
if id128 and os.path.isfile('/etc/machine-id'):
try:
test_content('f {} - - - - %m', '{}'.format(id128.get_machine().hex), user=user)
except AssertionError as e:
print(e)
print('/etc/machine-id: {!r}'.format(open('/etc/machine-id').read()))
print('/proc/cmdline: {!r}'.format(open('/proc/cmdline').read()))
print('skipping')
test_content('f {} - - - - %b', '{}'.format(id128.get_boot().hex), user=user)
test_content('f {} - - - - %H', '{}'.format(socket.gethostname()), user=user)
test_content('f {} - - - - %v', '{}'.format(os.uname().release), user=user)
test_content('f {} - - - - %U', '{}'.format(os.getuid() if user else 0), user=user)
test_content('f {} - - - - %G', '{}'.format(os.getgid() if user else 0), user=user)
try:
puser = pwd.getpwuid(os.getuid() if user else 0)
except KeyError:
puser = None
if puser:
test_content('f {} - - - - %u', '{}'.format(puser.pw_name), user=user)
try:
pgroup = grp.getgrgid(os.getgid() if user else 0)
except KeyError:
pgroup = None
if pgroup:
test_content('f {} - - - - %g', '{}'.format(pgroup.gr_name), user=user)
# Note that %h is the only specifier in which we look the environment,
# because we check $HOME. Should we even be doing that?
home = os.path.expanduser("~")
test_content('f {} - - - - %h', '{}'.format(home), user=user)
xdg_runtime_dir = os.getenv('XDG_RUNTIME_DIR')
if xdg_runtime_dir is not None or not user:
test_content('f {} - - - - %t',
xdg_runtime_dir if user else '/run',
user=user)
xdg_state_home = os.getenv('XDG_STATE_HOME')
if xdg_state_home is None and user:
xdg_state_home = os.path.join(home, ".local/state")
test_content('f {} - - - - %S',
xdg_state_home if user else '/var/lib',
user=user)
xdg_cache_home = os.getenv('XDG_CACHE_HOME')
if xdg_cache_home is None and user:
xdg_cache_home = os.path.join(home, ".cache")
test_content('f {} - - - - %C',
xdg_cache_home if user else '/var/cache',
user=user)
test_content('f {} - - - - %L',
os.path.join(xdg_state_home, 'log') if user else '/var/log',
user=user)
test_content('f {} - - - - %%', '%', user=user)
def mkfifo(parent, subpath):
os.makedirs(parent, mode=0o755, exist_ok=True)
first_component = subpath.split('/')[1]
path = parent + '/' + first_component
print('path: {}'.format(path))
os.mkfifo(path)
def mkdir(parent, subpath):
first_component = subpath.split('/')[1]
path = parent + '/' + first_component
os.makedirs(path, mode=0o755, exist_ok=True)
os.symlink(path, path + '/self', target_is_directory=True)
def symlink(parent, subpath):
link_path = parent + '/link-target'
os.makedirs(parent, mode=0o755, exist_ok=True)
with open(link_path, 'wb') as f:
f.write(b'target')
first_component = subpath.split('/')[1]
path = parent + '/' + first_component
os.symlink(link_path, path, target_is_directory=True)
def file(parent, subpath):
content = 'file-' + subpath.split('/')[1]
path = parent + subpath
os.makedirs(os.path.dirname(path), mode=0o755, exist_ok=True)
with open(path, 'wb') as f:
f.write(content.encode())
def valid_symlink(parent, subpath):
target = 'link-target'
link_path = parent + target
os.makedirs(link_path, mode=0o755, exist_ok=True)
first_component = subpath.split('/')[1]
path = parent + '/' + first_component
os.symlink(target, path, target_is_directory=True)
def test_hard_cleanup(*, user):
type_cbs = [None, file, mkdir, symlink]
if 'mkfifo' in dir(os):
type_cbs.append(mkfifo)
for type_cb in type_cbs:
for subpath in ['/shallow', '/deep/1/2']:
label = '{}-{}'.format('None' if type_cb is None else type_cb.__name__, subpath.split('/')[1])
test_content('f= {} - - - - ' + label, label, user=user, subpath=subpath, path_cb=type_cb)
# Test the case that a valid symlink is in the path.
label = 'valid_symlink-deep'
test_content('f= {} - - - - ' + label, label, user=user, subpath='/deep/1/2', path_cb=valid_symlink)
def test_base64():
test_content('f~ {} - - - - UGlmZgpQYWZmClB1ZmYgCg==', "Piff\nPaff\nPuff \n", user=False)
def test_conditionalized_execute_bit():
c = subprocess.run(exe_with_args + ['--version', '|', 'grep', '-F', '+ACL'], shell=True, stdout=subprocess.DEVNULL)
if c.returncode != 0:
return 0
d = tempfile.TemporaryDirectory(prefix='test-acl.', dir=temp_dir.name)
temp = Path(d.name) / "cond_exec"
temp.touch()
temp.chmod(0o644)
test_line(f"a {temp} - - - - u:root:Xwr", user=False, returncode=0)
c = subprocess.run(["getfacl", "-Ec", temp],
stdout=subprocess.PIPE, check=True, text=True)
assert "user:root:rw-" in c.stdout
temp.chmod(0o755)
test_line(f"a+ {temp} - - - - u:root:Xwr,g:root:rX", user=False, returncode=0)
c = subprocess.run(["getfacl", "-Ec", temp],
stdout=subprocess.PIPE, check=True, text=True)
assert "user:root:rwx" in c.stdout and "group:root:r-x" in c.stdout
if __name__ == '__main__':
test_invalids(user=False)
test_invalids(user=True)
test_uninitialized_t()
test_valid_specifiers(user=False)
test_valid_specifiers(user=True)
test_hard_cleanup(user=False)
test_hard_cleanup(user=True)
test_base64()
test_conditionalized_execute_bit()