projects/linux·blob master · refs

156 lines · 3.3 KiB

1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3
4set -e
5set -u
6set -o pipefail
7
8IMA_POLICY_FILE="/sys/kernel/security/ima/policy"
9TEST_BINARY="/bin/true"
10VERBOSE="${SELFTESTS_VERBOSE:=0}"
11LOG_FILE="$(mktemp /tmp/ima_setup.XXXX.log)"
12
13usage()
14{
15 echo "Usage: $0 <setup|cleanup|run|modify-bin|restore-bin|load-policy> <existing_tmp_dir>"
16 exit 1
17}
18
19ensure_mount_securityfs()
20{
21 local securityfs_dir=$(grep "securityfs" /proc/mounts | awk '{print $2}')
22
23 if [ -z "${securityfs_dir}" ]; then
24 securityfs_dir=/sys/kernel/security
25 mount -t securityfs security "${securityfs_dir}"
26 fi
27
28 if [ ! -d "${securityfs_dir}" ]; then
29 echo "${securityfs_dir}: securityfs is not mounted" && exit 1
30 fi
31}
32
33setup()
34{
35 local tmp_dir="$1"
36 local mount_img="${tmp_dir}/test.img"
37 local mount_dir="${tmp_dir}/mnt"
38 local copied_bin_path="${mount_dir}/$(basename ${TEST_BINARY})"
39 mkdir -p ${mount_dir}
40
41 dd if=/dev/zero of="${mount_img}" bs=1M count=10
42
43 losetup -f "${mount_img}"
44 local loop_device=$(losetup -a | grep ${mount_img:?} | cut -d ":" -f1)
45
46 mkfs.ext2 "${loop_device:?}"
47 mount "${loop_device}" "${mount_dir}"
48
49 cp "${TEST_BINARY}" "${mount_dir}"
50 local mount_uuid="$(blkid ${loop_device} | sed 's/.*UUID="\([^"]*\)".*/\1/')"
51
52 ensure_mount_securityfs
53 echo "measure func=BPRM_CHECK fsuuid=${mount_uuid}" > ${IMA_POLICY_FILE}
54 echo "measure func=BPRM_CHECK fsuuid=${mount_uuid}" > ${mount_dir}/policy_test
55}
56
57cleanup() {
58 local tmp_dir="$1"
59 local mount_img="${tmp_dir}/test.img"
60 local mount_dir="${tmp_dir}/mnt"
61
62 local loop_devices=$(losetup -a | grep ${mount_img:?} | cut -d ":" -f1)
63
64 for loop_dev in "${loop_devices}"; do
65 losetup -d $loop_dev
66 done
67
68 umount ${mount_dir}
69 rm -rf ${tmp_dir}
70}
71
72run()
73{
74 local tmp_dir="$1"
75 local mount_dir="${tmp_dir}/mnt"
76 local copied_bin_path="${mount_dir}/$(basename ${TEST_BINARY})"
77
78 exec "${copied_bin_path}"
79}
80
81modify_bin()
82{
83 local tmp_dir="$1"
84 local mount_dir="${tmp_dir}/mnt"
85 local copied_bin_path="${mount_dir}/$(basename ${TEST_BINARY})"
86
87 echo "mod" >> "${copied_bin_path}"
88}
89
90restore_bin()
91{
92 local tmp_dir="$1"
93 local mount_dir="${tmp_dir}/mnt"
94 local copied_bin_path="${mount_dir}/$(basename ${TEST_BINARY})"
95
96 truncate -s -4 "${copied_bin_path}"
97}
98
99load_policy()
100{
101 local tmp_dir="$1"
102 local mount_dir="${tmp_dir}/mnt"
103
104 echo ${mount_dir}/policy_test > ${IMA_POLICY_FILE} 2> /dev/null
105}
106
107catch()
108{
109 local exit_code="$1"
110 local log_file="$2"
111
112 if [[ "${exit_code}" -ne 0 ]]; then
113 cat "${log_file}" >&3
114 fi
115
116 rm -f "${log_file}"
117 exit ${exit_code}
118}
119
120main()
121{
122 [[ $# -ne 2 ]] && usage
123
124 local action="$1"
125 local tmp_dir="$2"
126
127 [[ ! -d "${tmp_dir}" ]] && echo "Directory ${tmp_dir} doesn't exist" && exit 1
128
129 if [[ "${action}" == "setup" ]]; then
130 setup "${tmp_dir}"
131 elif [[ "${action}" == "cleanup" ]]; then
132 cleanup "${tmp_dir}"
133 elif [[ "${action}" == "run" ]]; then
134 run "${tmp_dir}"
135 elif [[ "${action}" == "modify-bin" ]]; then
136 modify_bin "${tmp_dir}"
137 elif [[ "${action}" == "restore-bin" ]]; then
138 restore_bin "${tmp_dir}"
139 elif [[ "${action}" == "load-policy" ]]; then
140 load_policy "${tmp_dir}"
141 else
142 echo "Unknown action: ${action}"
143 exit 1
144 fi
145}
146
147trap 'catch "$?" "${LOG_FILE}"' EXIT
148
149if [[ "${VERBOSE}" -eq 0 ]]; then
150 # Save the stderr to 3 so that we can output back to
151 # it incase of an error.
152 exec 3>&2 1>"${LOG_FILE}" 2>&1
153fi
154
155main "$@"
156rm -f "${LOG_FILE}"