systemd/test/units/TEST-43-PRIVATEUSER-UNPRIV.sh

#!/usr/bin/env bash
# SPDX-License-Identifier: LGPL-2.1-or-later
set -eux
set -o pipefail

# shellcheck source=test/units/util.sh
. "$(dirname "$0")"/util.sh

if [[ "$(sysctl -ne kernel.apparmor_restrict_unprivileged_userns)" -eq 1 ]]; then
    echo "Cannot create unprivileged user namespaces" >/skipped
    exit 77
fi

install_extension_images

systemd-analyze log-level debug

runas testuser systemd-run --wait --user --unit=test-private-users \
    -p PrivateUsers=yes -P echo hello

runas testuser systemctl --user log-level debug

runas testuser systemd-run --wait --user --unit=test-private-tmp-innerfile \
    -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 PrivateTmp=yes \
    -P test ! -e /tmp/outerfile.txt

# Confirm that creating a file in home works
runas testuser systemd-run --wait --user --unit=test-unprotected-home \
    -P touch /home/testuser/works.txt
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 ProtectHome=read-only \
    -P bash -c '
        test -e /home/testuser/works.txt || exit 10
        touch /home/testuser/blocked.txt && exit 11
    ')
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 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 ProtectHome=yes \
    -P bash -c '
        test "$(stat -c %a /home)" = "0"
        test "$(stat -c %a /root)" = "0"
        test "$(stat -c %a /run/user)" = "0"
    '

# Confirm we cannot change groups because we only have one mapping in the user
# namespace (no CAP_SETGID in the parent namespace to write the additional
# mapping of the user supplied group and thus cannot change groups to an
# unmapped group ID)
(! runas testuser systemd-run --wait --user --unit=test-group-fail \
    -p PrivateUsers=yes -p Group=daemon \
    -P true)

# 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 BindPaths=/dev/null:/etc/os-release \
    test ! -s /etc/os-release

runas testuser systemd-run --wait --user --unit=test-read-write \
    -p ReadOnlyPaths=/ \
    -p ReadWritePaths="/var /run /tmp" \
    -p NoExecPaths=/ -p ExecPaths=/usr \
    test ! -w /etc/os-release

runas testuser systemd-run --wait --user --unit=test-caps \
    -p PrivateUsers=yes -p AmbientCapabilities=CAP_SYS_ADMIN \
    -p CapabilityBoundingSet=CAP_SYS_ADMIN \
    test -s /etc/os-release

runas testuser systemd-run --wait --user --unit=test-devices \
    -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 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 ProtectHostname=yes \
    hostnamectl hostname foo)

(! runas testuser systemd-run --wait --user --unit=test-clock \
    -p ProtectClock=yes \
    timedatectl set-time "2012-10-30 18:17:16")

(! runas testuser systemd-run --wait --user --unit=test-kernel-tunable \
    -p ProtectKernelTunables=yes \
    sh -c "echo 0 >/proc/sys/user/max_user_namespaces")

(! runas testuser systemd-run --wait --user --unit=test-kernel-mod \
    -p ProtectKernelModules=yes \
    sh -c "modprobe -r overlay && modprobe overlay")

if sysctl kernel.dmesg_restrict=0; then
    (! runas testuser systemd-run --wait --user --unit=test-kernel-log \
        -p ProtectKernelLogs=yes -p LogNamespace=yes \
        dmesg)
fi

unsquashfs -no-xattrs -d /tmp/img /usr/share/minimal_0.raw
runas testuser systemd-run --wait --user --unit=test-root-dir \
    -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 RootDirectory=/tmp/img_bind -p MountFlags=private \
    grep MARKER=1 /etc/os-release
umount /tmp/img_bind

# Unprivileged overlayfs was added to Linux 5.11, so try to detect it first
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 /tmp/app1.raw
    runas testuser systemd-run --wait --user --unit=test-extension-dir \
        -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
fi

systemd-analyze log-level info

touch /testok