Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 | // SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2020 Google LLC. */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/wait.h> #include <test_progs.h> #include <linux/ring_buffer.h> #include "ima.skel.h" #define MAX_SAMPLES 4 static int _run_measured_process(const char *measured_dir, u32 *monitored_pid, const char *cmd) { int child_pid, child_status; child_pid = fork(); if (child_pid == 0) { *monitored_pid = getpid(); execlp("./ima_setup.sh", "./ima_setup.sh", cmd, measured_dir, NULL); exit(errno); } else if (child_pid > 0) { waitpid(child_pid, &child_status, 0); return WEXITSTATUS(child_status); } return -EINVAL; } static int run_measured_process(const char *measured_dir, u32 *monitored_pid) { return _run_measured_process(measured_dir, monitored_pid, "run"); } static u64 ima_hash_from_bpf[MAX_SAMPLES]; static int ima_hash_from_bpf_idx; static int process_sample(void *ctx, void *data, size_t len) { if (ima_hash_from_bpf_idx >= MAX_SAMPLES) return -ENOSPC; ima_hash_from_bpf[ima_hash_from_bpf_idx++] = *((u64 *)data); return 0; } static void test_init(struct ima__bss *bss) { ima_hash_from_bpf_idx = 0; bss->use_ima_file_hash = false; bss->enable_bprm_creds_for_exec = false; bss->enable_kernel_read_file = false; bss->test_deny = false; } void test_test_ima(void) { char measured_dir_template[] = "/tmp/ima_measuredXXXXXX"; struct ring_buffer *ringbuf = NULL; const char *measured_dir; u64 bin_true_sample; char cmd[256]; int err, duration = 0; struct ima *skel = NULL; skel = ima__open_and_load(); if (CHECK(!skel, "skel_load", "skeleton failed\n")) goto close_prog; ringbuf = ring_buffer__new(bpf_map__fd(skel->maps.ringbuf), process_sample, NULL, NULL); if (!ASSERT_OK_PTR(ringbuf, "ringbuf")) goto close_prog; err = ima__attach(skel); if (CHECK(err, "attach", "attach failed: %d\n", err)) goto close_prog; measured_dir = mkdtemp(measured_dir_template); if (CHECK(measured_dir == NULL, "mkdtemp", "err %d\n", errno)) goto close_prog; snprintf(cmd, sizeof(cmd), "./ima_setup.sh setup %s", measured_dir); err = system(cmd); if (CHECK(err, "failed to run command", "%s, errno = %d\n", cmd, errno)) goto close_clean; /* * Test #1 * - Goal: obtain a sample with the bpf_ima_inode_hash() helper * - Expected result: 1 sample (/bin/true) */ test_init(skel->bss); err = run_measured_process(measured_dir, &skel->bss->monitored_pid); if (CHECK(err, "run_measured_process #1", "err = %d\n", err)) goto close_clean; err = ring_buffer__consume(ringbuf); ASSERT_EQ(err, 1, "num_samples_or_err"); ASSERT_NEQ(ima_hash_from_bpf[0], 0, "ima_hash"); /* * Test #2 * - Goal: obtain samples with the bpf_ima_file_hash() helper * - Expected result: 2 samples (./ima_setup.sh, /bin/true) */ test_init(skel->bss); skel->bss->use_ima_file_hash = true; err = run_measured_process(measured_dir, &skel->bss->monitored_pid); if (CHECK(err, "run_measured_process #2", "err = %d\n", err)) goto close_clean; err = ring_buffer__consume(ringbuf); ASSERT_EQ(err, 2, "num_samples_or_err"); ASSERT_NEQ(ima_hash_from_bpf[0], 0, "ima_hash"); ASSERT_NEQ(ima_hash_from_bpf[1], 0, "ima_hash"); bin_true_sample = ima_hash_from_bpf[1]; /* * Test #3 * - Goal: confirm that bpf_ima_inode_hash() returns a non-fresh digest * - Expected result: 2 samples (/bin/true: non-fresh, fresh) */ test_init(skel->bss); err = _run_measured_process(measured_dir, &skel->bss->monitored_pid, "modify-bin"); if (CHECK(err, "modify-bin #3", "err = %d\n", err)) goto close_clean; skel->bss->enable_bprm_creds_for_exec = true; err = run_measured_process(measured_dir, &skel->bss->monitored_pid); if (CHECK(err, "run_measured_process #3", "err = %d\n", err)) goto close_clean; err = ring_buffer__consume(ringbuf); ASSERT_EQ(err, 2, "num_samples_or_err"); ASSERT_NEQ(ima_hash_from_bpf[0], 0, "ima_hash"); ASSERT_NEQ(ima_hash_from_bpf[1], 0, "ima_hash"); ASSERT_EQ(ima_hash_from_bpf[0], bin_true_sample, "sample_equal_or_err"); /* IMA refreshed the digest. */ ASSERT_NEQ(ima_hash_from_bpf[1], bin_true_sample, "sample_different_or_err"); /* * Test #4 * - Goal: verify that bpf_ima_file_hash() returns a fresh digest * - Expected result: 4 samples (./ima_setup.sh: fresh, fresh; * /bin/true: fresh, fresh) */ test_init(skel->bss); skel->bss->use_ima_file_hash = true; skel->bss->enable_bprm_creds_for_exec = true; err = run_measured_process(measured_dir, &skel->bss->monitored_pid); if (CHECK(err, "run_measured_process #4", "err = %d\n", err)) goto close_clean; err = ring_buffer__consume(ringbuf); ASSERT_EQ(err, 4, "num_samples_or_err"); ASSERT_NEQ(ima_hash_from_bpf[0], 0, "ima_hash"); ASSERT_NEQ(ima_hash_from_bpf[1], 0, "ima_hash"); ASSERT_NEQ(ima_hash_from_bpf[2], 0, "ima_hash"); ASSERT_NEQ(ima_hash_from_bpf[3], 0, "ima_hash"); ASSERT_NEQ(ima_hash_from_bpf[2], bin_true_sample, "sample_different_or_err"); ASSERT_EQ(ima_hash_from_bpf[3], ima_hash_from_bpf[2], "sample_equal_or_err"); skel->bss->use_ima_file_hash = false; skel->bss->enable_bprm_creds_for_exec = false; err = _run_measured_process(measured_dir, &skel->bss->monitored_pid, "restore-bin"); if (CHECK(err, "restore-bin #3", "err = %d\n", err)) goto close_clean; /* * Test #5 * - Goal: obtain a sample from the kernel_read_file hook * - Expected result: 2 samples (./ima_setup.sh, policy_test) */ test_init(skel->bss); skel->bss->use_ima_file_hash = true; skel->bss->enable_kernel_read_file = true; err = _run_measured_process(measured_dir, &skel->bss->monitored_pid, "load-policy"); if (CHECK(err, "run_measured_process #5", "err = %d\n", err)) goto close_clean; err = ring_buffer__consume(ringbuf); ASSERT_EQ(err, 2, "num_samples_or_err"); ASSERT_NEQ(ima_hash_from_bpf[0], 0, "ima_hash"); ASSERT_NEQ(ima_hash_from_bpf[1], 0, "ima_hash"); /* * Test #6 * - Goal: ensure that the kernel_read_file hook denies an operation * - Expected result: 0 samples */ test_init(skel->bss); skel->bss->enable_kernel_read_file = true; skel->bss->test_deny = true; err = _run_measured_process(measured_dir, &skel->bss->monitored_pid, "load-policy"); if (CHECK(!err, "run_measured_process #6", "err = %d\n", err)) goto close_clean; err = ring_buffer__consume(ringbuf); ASSERT_EQ(err, 0, "num_samples_or_err"); close_clean: snprintf(cmd, sizeof(cmd), "./ima_setup.sh cleanup %s", measured_dir); err = system(cmd); CHECK(err, "failed to run command", "%s, errno = %d\n", cmd, errno); close_prog: ring_buffer__free(ringbuf); ima__destroy(skel); } |