From: Roberto Sassu <[email protected]> Add tests to verify the correctness of the Integrity Digest Cache, in all_test.c.
Add the kernel module digest_cache_kern.ko, to let all_test call the API of the Integrity Digest Cache through the newly introduced digest_cache_test file in <securityfs>/integrity/digest_cache. Test coverage information: File 'security/integrity/digest_cache/reset.c' Lines executed:100.00% of 53 File 'security/integrity/digest_cache/main.c' Lines executed:90.29% of 206 File 'security/integrity/digest_cache/modsig.c' Lines executed:42.86% of 21 File 'security/integrity/digest_cache/htable.c' Lines executed:93.90% of 82 File 'security/integrity/digest_cache/populate.c' Lines executed:89.19% of 37 File 'security/integrity/digest_cache/verif.c' Lines executed:85.11% of 47 File 'security/integrity/digest_cache/dir.c' Lines executed:90.18% of 163 File 'security/integrity/digest_cache/parsers.c' Lines executed:45.74% of 94 File 'security/integrity/digest_cache/secfs.c' Lines executed:56.00% of 25 File 'security/integrity/digest_cache/parsers/tlv.c' Lines executed:75.26% of 97 Signed-off-by: Roberto Sassu <[email protected]> --- tools/testing/selftests/Makefile | 1 + .../testing/selftests/digest_cache/.gitignore | 3 + tools/testing/selftests/digest_cache/Makefile | 24 + .../testing/selftests/digest_cache/all_test.c | 769 ++++++++++++++++++ tools/testing/selftests/digest_cache/common.c | 78 ++ tools/testing/selftests/digest_cache/common.h | 93 +++ .../selftests/digest_cache/common_user.c | 33 + .../selftests/digest_cache/common_user.h | 15 + tools/testing/selftests/digest_cache/config | 2 + .../selftests/digest_cache/generators.c | 130 +++ .../selftests/digest_cache/generators.h | 16 + .../selftests/digest_cache/testmod/Makefile | 16 + .../selftests/digest_cache/testmod/kern.c | 551 +++++++++++++ 13 files changed, 1731 insertions(+) create mode 100644 tools/testing/selftests/digest_cache/.gitignore create mode 100644 tools/testing/selftests/digest_cache/Makefile create mode 100644 tools/testing/selftests/digest_cache/all_test.c create mode 100644 tools/testing/selftests/digest_cache/common.c create mode 100644 tools/testing/selftests/digest_cache/common.h create mode 100644 tools/testing/selftests/digest_cache/common_user.c create mode 100644 tools/testing/selftests/digest_cache/common_user.h create mode 100644 tools/testing/selftests/digest_cache/config create mode 100644 tools/testing/selftests/digest_cache/generators.c create mode 100644 tools/testing/selftests/digest_cache/generators.h create mode 100644 tools/testing/selftests/digest_cache/testmod/Makefile create mode 100644 tools/testing/selftests/digest_cache/testmod/kern.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index b38199965f99..e6fc3c984923 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -16,6 +16,7 @@ TARGETS += cpu-hotplug TARGETS += damon TARGETS += devices/error_logs TARGETS += devices/probe +TARGETS += digest_cache TARGETS += dmabuf-heaps TARGETS += drivers/dma-buf TARGETS += drivers/s390x/uvdevice diff --git a/tools/testing/selftests/digest_cache/.gitignore b/tools/testing/selftests/digest_cache/.gitignore new file mode 100644 index 000000000000..392096e18f4e --- /dev/null +++ b/tools/testing/selftests/digest_cache/.gitignore @@ -0,0 +1,3 @@ +/*.mod +/*_test +/*.ko diff --git a/tools/testing/selftests/digest_cache/Makefile b/tools/testing/selftests/digest_cache/Makefile new file mode 100644 index 000000000000..1b819201f406 --- /dev/null +++ b/tools/testing/selftests/digest_cache/Makefile @@ -0,0 +1,24 @@ +# SPDX-License-Identifier: GPL-2.0 +TEST_GEN_PROGS_EXTENDED = digest_cache_kern.ko +TEST_GEN_PROGS := all_test + +$(OUTPUT)/%.ko: $(wildcard common.[ch]) testmod/Makefile testmod/kern.c + $(call msg,MOD,,$@) + $(Q)$(MAKE) -C testmod + $(Q)cp testmod/digest_cache_kern.ko $@ + +LOCAL_HDRS += common.h common_user.h generators.h +CFLAGS += -ggdb -Wall -Wextra $(KHDR_INCLUDES) + +OVERRIDE_TARGETS := 1 +override define CLEAN + $(call msg,CLEAN) + $(Q)$(MAKE) -C testmod clean + rm -Rf $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) + rm -Rf $(OUTPUT)/common.o $(OUTPUT)/common_user.o $(OUTPUT)/generators.o + rm -Rf $(OUTPUT)/common.mod +endef + +include ../lib.mk + +$(OUTPUT)/all_test: common.c common.h common_user.c common_user.h generators.c diff --git a/tools/testing/selftests/digest_cache/all_test.c b/tools/testing/selftests/digest_cache/all_test.c new file mode 100644 index 000000000000..a283068f3cab --- /dev/null +++ b/tools/testing/selftests/digest_cache/all_test.c @@ -0,0 +1,769 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Implement the tests of the Integrity Digest Cache. + */ + +#include <errno.h> +#include <fcntl.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <limits.h> +#include <fts.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/xattr.h> +#include <sys/syscall.h> +#include <linux/module.h> + +#include "generators.h" + +#include "../kselftest_harness.h" +#include "../../../../include/uapi/linux/xattr.h" + +#define BASE_DIR_TEMPLATE "/tmp/digest_cache_test_dirXXXXXX" +#define DIGEST_LISTS_SUBDIR "digest_lists" +#define NUM_DIGEST_LISTS_PREFETCH MAX_WORKS + +FIXTURE(shared_data) { + char base_dir[sizeof(BASE_DIR_TEMPLATE)]; + char digest_lists_dir[sizeof(BASE_DIR_TEMPLATE) + + sizeof(DIGEST_LISTS_SUBDIR)]; + int base_dirfd, digest_lists_dirfd, kernfd, pathfd, cmd_len, no_kprobe; +}; + +FIXTURE_SETUP(shared_data) +{ + char cmd[1024]; + int ret, fd, i, cmd_len; + + /* Create the base directory. */ + snprintf(self->base_dir, sizeof(self->base_dir), BASE_DIR_TEMPLATE); + ASSERT_NE(NULL, mkdtemp(self->base_dir)); + + /* Open base directory. */ + self->base_dirfd = open(self->base_dir, O_RDONLY | O_DIRECTORY); + ASSERT_NE(-1, self->base_dirfd); + + /* Create the digest_lists subdirectory. */ + snprintf(self->digest_lists_dir, sizeof(self->digest_lists_dir), + "%s/%s", self->base_dir, DIGEST_LISTS_SUBDIR); + ASSERT_EQ(0, mkdirat(self->base_dirfd, DIGEST_LISTS_SUBDIR, 0600)); + self->digest_lists_dirfd = openat(self->base_dirfd, DIGEST_LISTS_SUBDIR, + O_RDONLY | O_DIRECTORY); + ASSERT_NE(-1, self->digest_lists_dirfd); + + fd = open("digest_cache_kern.ko", O_RDONLY); + ASSERT_LT(0, fd); + + ASSERT_EQ(0, syscall(SYS_finit_module, fd, "", 0)); + close(fd); + + /* Open kernel test interface. */ + self->kernfd = open(DIGEST_CACHE_TEST_INTERFACE, O_RDWR, 0600); + ASSERT_NE(-1, self->kernfd); + + /* Open kernel digest list path interface. */ + self->pathfd = open(DIGEST_CACHE_PATH_INTERFACE, O_RDWR, 0600); + ASSERT_NE(-1, self->pathfd); + + /* Write the path of the digest lists directory. */ + ASSERT_LT(0, write(self->pathfd, self->digest_lists_dir, + strlen(self->digest_lists_dir))); + + /* Ensure that no verifier is enabled at the beginning of a test. */ + for (i = 0; i < VERIF__LAST; i++) { + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s", + commands_str[DIGEST_CACHE_DISABLE_VERIF], + verifs_str[i]); + ret = write(self->kernfd, cmd, cmd_len); + if (ret < 0 && errno == EOPNOTSUPP) { + self->no_kprobe = 1; + break; + } + + ASSERT_EQ(cmd_len, ret); + } +} + +FIXTURE_TEARDOWN(shared_data) +{ + FTS *fts = NULL; + FTSENT *ftsent; + int fts_flags = (FTS_PHYSICAL | FTS_COMFOLLOW | FTS_NOCHDIR | FTS_XDEV); + char *paths[2] = { self->base_dir, NULL }; + char cmd[1024]; + int cmd_len; + + /* Close digest_lists subdirectory. */ + close(self->digest_lists_dirfd); + + /* Close base directory. */ + close(self->base_dirfd); + + /* Delete files and directories. */ + fts = fts_open(paths, fts_flags, NULL); + if (fts) { + while ((ftsent = fts_read(fts)) != NULL) { + switch (ftsent->fts_info) { + case FTS_DP: + rmdir(ftsent->fts_accpath); + break; + case FTS_F: + case FTS_SL: + case FTS_SLNONE: + case FTS_DEFAULT: + unlink(ftsent->fts_accpath); + break; + default: + break; + } + } + } + + /* Release digest cache reference, if the test was interrupted. */ + cmd_len = snprintf(cmd, sizeof(cmd), "%s", + commands_str[DIGEST_CACHE_PUT]); + write(self->kernfd, cmd, cmd_len); + + /* Close kernel test interface. */ + close(self->kernfd); + + /* Close kernel digest list path interface. */ + close(self->pathfd); + + syscall(SYS_delete_module, "digest_cache_kern", 0); +} + +static int _query_test(int kernfd, char *base_dir, char *filename, + enum hash_algo algo, int start_number, int num_digests, + bool write_digest_list, int digest_lists_dirfd, + char *digest_list_filename) +{ + u8 digest[MAX_DIGEST_SIZE] = { 0 }; + char digest_str[MAX_DIGEST_SIZE * 2 + 1] = { 0 }; + int digest_len = hash_digest_size[algo]; + char cmd[1024]; + int ret, fd, i, cmd_len; + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/%s", + commands_str[DIGEST_CACHE_GET], base_dir, filename); + ret = write(kernfd, cmd, cmd_len); + if (ret != cmd_len) + return -errno; + + if (write_digest_list) { + fd = openat(digest_lists_dirfd, digest_list_filename, O_WRONLY); + if (fd < 0) + return -errno; + + close(fd); + } + + ret = 0; + + *(u32 *)digest = start_number; + + for (i = 0; i < num_digests; i++) { + bin2hex(digest_str, digest, digest_len); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/%s|%s:%s", + commands_str[DIGEST_CACHE_LOOKUP], base_dir, + filename, hash_algo_name[algo], digest_str); + ret = write(kernfd, cmd, cmd_len); + if (ret != cmd_len) { + ret = -errno; + goto out; + } else { + ret = 0; + } + + (*(u32 *)digest)++; + } +out: + cmd_len = snprintf(cmd, sizeof(cmd), "%s", + commands_str[DIGEST_CACHE_PUT]); + write(kernfd, cmd, cmd_len); + return ret; +} + +static int query_test(int kernfd, char *base_dir, char *filename, + enum hash_algo algo, int start_number, int num_digests) +{ + return _query_test(kernfd, base_dir, filename, algo, start_number, + num_digests, false, -1, NULL); +} + +static int query_test_write(int kernfd, char *base_dir, char *filename, + enum hash_algo algo, int start_number, + int num_digests, int digest_lists_dirfd, + char *digest_list_filename) +{ + return _query_test(kernfd, base_dir, filename, algo, start_number, + num_digests, true, digest_lists_dirfd, + digest_list_filename); +} + +static void test_parser(struct _test_data_shared_data *self, + struct __test_metadata *_metadata, + char *digest_list_filename, char *filename, + enum hash_algo algo, int start_number, int num_digests, + unsigned int failure) +{ + int expected_ret = (failure) ? -ENOENT : 0; + + if (!strncmp(digest_list_filename, "tlv-", 4)) { + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, + digest_list_filename, algo, + start_number, num_digests, + (enum tlv_failures)failure)); + } + + ASSERT_EQ(0, create_file(self->base_dirfd, filename, + digest_list_filename)); + ASSERT_EQ(expected_ret, query_test(self->kernfd, self->base_dir, + filename, algo, start_number, + num_digests)); + + unlinkat(self->digest_lists_dirfd, digest_list_filename, 0); + unlinkat(self->base_dirfd, filename, 0); +} + +/* + * Verify that the tlv digest list parser returns success on well-formatted + * digest lists, for each defined hash algorithm. + */ +TEST_F(shared_data, tlv_parser_ok) +{ + enum hash_algo algo; + + /* Test every known algorithm. */ + for (algo = 0; algo < HASH_ALGO__LAST; algo++) + test_parser(self, _metadata, "tlv-digest_list", "file", algo, + 0, 5, TLV_NO_FAILURE); +} + +/* + * Verify that the tlv digest list parser returns failure on invalid digest + * lists. + */ +TEST_F(shared_data, tlv_parser_error) +{ + enum tlv_failures failure; + + /* Test every failure. */ + for (failure = 0; failure < TLV_FAILURE__LAST; failure++) + test_parser(self, _metadata, "tlv-digest_list", "file", + HASH_ALGO_SHA224, 0, 1, failure); +} + +static void test_default_path(struct _test_data_shared_data *self, + struct __test_metadata *_metadata, bool file) +{ + char path[PATH_MAX]; + size_t path_len; + + if (file) { + path_len = snprintf(path, sizeof(path), + "%s/%s/tlv-digest_list", self->base_dir, + DIGEST_LISTS_SUBDIR); + ASSERT_LT(0, write(self->pathfd, path, path_len)); + } + + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, "tlv-digest_list", + HASH_ALGO_SHA1, 0, 1, TLV_NO_FAILURE)); + + ASSERT_EQ(0, create_file(self->base_dirfd, "file", NULL)); + + ASSERT_EQ(0, query_test(self->kernfd, self->base_dir, "file", + HASH_ALGO_SHA1, 0, 1)); +} + +/* + * Verify that the digest cache created from the default path (regular file) + * can be retrieved and used for lookup. + */ +TEST_F(shared_data, default_path_file) +{ + test_default_path(self, _metadata, true); +} + +/* + * Verify that the digest cache created from the default path (directory) + * can be retrieved and used for lookup. + */ +TEST_F(shared_data, default_path_dir) +{ + test_default_path(self, _metadata, false); +} + +static void test_file_changes(struct _test_data_shared_data *self, + struct __test_metadata *_metadata, + enum file_changes change) +{ + char digest_list_filename[] = "tlv-digest_list"; + char digest_list_filename_new[] = "tlv-digest_list6"; + char digest_list_filename_xattr[] = "tlv-digest_list7"; + char digest_list_path[sizeof(self->digest_lists_dir) + + sizeof(digest_list_filename)]; + int fd; + + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, + digest_list_filename, HASH_ALGO_SHA1, 0, 1, + TLV_NO_FAILURE)); + + ASSERT_EQ(0, create_file(self->base_dirfd, "file", + digest_list_filename)); + + ASSERT_EQ(0, query_test(self->kernfd, self->base_dir, "file", + HASH_ALGO_SHA1, 0, 1)); + + switch (change) { + case FILE_WRITE: + fd = openat(self->digest_lists_dirfd, digest_list_filename, + O_WRONLY); + ASSERT_NE(-1, fd); + + ASSERT_EQ(4, write(fd, "1234", 4)); + close(fd); + break; + case FILE_TRUNCATE: + snprintf(digest_list_path, sizeof(digest_list_path), + "%s/%s", self->digest_lists_dir, digest_list_filename); + ASSERT_EQ(0, truncate(digest_list_path, 4)); + break; + case FILE_FTRUNCATE: + fd = openat(self->digest_lists_dirfd, digest_list_filename, + O_WRONLY); + ASSERT_NE(-1, fd); + ASSERT_EQ(0, ftruncate(fd, 4)); + close(fd); + break; + case FILE_UNLINK: + ASSERT_EQ(0, unlinkat(self->digest_lists_dirfd, + digest_list_filename, 0)); + break; + case FILE_RENAME: + ASSERT_EQ(0, renameat(self->digest_lists_dirfd, + digest_list_filename, + self->digest_lists_dirfd, + digest_list_filename_new)); + break; + case FILE_SETXATTR: + fd = openat(self->base_dirfd, "file", O_WRONLY); + ASSERT_NE(-1, fd); + + ASSERT_EQ(0, fsetxattr(fd, XATTR_NAME_DIGEST_LIST, + digest_list_filename_xattr, + strlen(digest_list_filename_xattr) + 1, + 0)); + close(fd); + break; + case FILE_REMOVEXATTR: + fd = openat(self->base_dirfd, "file", O_WRONLY); + ASSERT_NE(-1, fd); + + ASSERT_EQ(0, fremovexattr(fd, XATTR_NAME_DIGEST_LIST)); + close(fd); + + /* + * Removing security.digest_list does not cause a failure, + * the digest can be still retrieved via directory lookup. + */ + ASSERT_EQ(0, query_test(self->kernfd, self->base_dir, "file", + HASH_ALGO_SHA1, 0, 1)); + + return; + default: + break; + } + + ASSERT_NE(0, query_test(self->kernfd, self->base_dir, "file", + HASH_ALGO_SHA1, 0, 1)); +} + +/* + * Verify that operations on a digest list cause a reset of the digest cache, + * and that the digest is not found in the invalid/missing digest list. + */ +TEST_F(shared_data, file_reset) +{ + enum file_changes change; + + /* Test for every file change. */ + for (change = 0; change < FILE_CHANGE__LAST; change++) + test_file_changes(self, _metadata, change); +} + +/* + * Verify that digest lookup does not work after a reset, and attempt the + * query a second time, which should instead succeed. + */ +TEST_F(shared_data, file_reset_again) +{ + char digest_list_filename[] = "tlv-digest_list"; + + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, + digest_list_filename, HASH_ALGO_SHA1, 0, 1, + TLV_NO_FAILURE)); + + ASSERT_EQ(0, create_file(self->base_dirfd, "file", + digest_list_filename)); + + ASSERT_NE(0, query_test_write(self->kernfd, self->base_dir, "file", + HASH_ALGO_SHA1, 0, 1, + self->digest_lists_dirfd, + digest_list_filename)); + + ASSERT_EQ(0, query_test(self->kernfd, self->base_dir, "file", + HASH_ALGO_SHA1, 0, 1)); +} + +static void query_test_with_failures(struct _test_data_shared_data *self, + struct __test_metadata *_metadata, + int start_number, int num_digests, + int *removed, int num_removed) +{ + char filename[NAME_MAX + 1]; + int i, j, expected_ret; + + for (i = start_number; i < start_number + num_digests; i++) { + expected_ret = 0; + + for (j = 0; j < num_removed; j++) { + if (removed[j] == i) { + expected_ret = -ENOENT; + break; + } + } + + snprintf(filename, sizeof(filename), "file%d", i); + + ASSERT_EQ(expected_ret, query_test(self->kernfd, self->base_dir, + filename, HASH_ALGO_SHA1, i, + 1)); + } +} + +/* + * Verify that changes in the digest list directory are monitored and that + * a digest cannot be found if the respective digest list file has been moved + * away from the directory, and that a digest can be found if the respective + * digest list has been moved/created in the directory. + */ +TEST_F(shared_data, dir_reset) +{ + char filename[NAME_MAX + 1]; + int i, removed[10]; + + for (i = 0; i < 10; i++) { + snprintf(filename, sizeof(filename), "file%d", i); + ASSERT_EQ(0, create_file(self->base_dirfd, filename, NULL)); + snprintf(filename, sizeof(filename), "tlv-digest_list%d", i); + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, + filename, HASH_ALGO_SHA1, i, 1, + TLV_NO_FAILURE)); + } + + query_test_with_failures(self, _metadata, 0, 10, removed, 0); + + ASSERT_EQ(0, unlinkat(self->digest_lists_dirfd, "tlv-digest_list7", 0)); + + removed[0] = 7; + + query_test_with_failures(self, _metadata, 0, 10, removed, 1); + + ASSERT_EQ(0, renameat(self->digest_lists_dirfd, "tlv-digest_list6", + self->base_dirfd, "tlv-digest_list6")); + + removed[1] = 6; + + query_test_with_failures(self, _metadata, 0, 10, removed, 2); + + ASSERT_EQ(0, renameat(self->base_dirfd, "tlv-digest_list6", + self->digest_lists_dirfd, "tlv-digest_list6")); + + query_test_with_failures(self, _metadata, 0, 10, removed, 1); + + ASSERT_EQ(0, create_file(self->base_dirfd, "file10", NULL)); + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, "tlv-digest_list10", + HASH_ALGO_SHA1, 10, 1, TLV_NO_FAILURE)); + + query_test_with_failures(self, _metadata, 0, 11, removed, 1); +} + +static void _check_verif_data(struct _test_data_shared_data *self, + struct __test_metadata *_metadata, + char *digest_list_filename, int num, + enum hash_algo algo, bool check_dir) +{ + char digest_list_filename_kernel[NAME_MAX + 1]; + char cmd[1024], number[20]; + u8 digest[MAX_DIGEST_SIZE] = { 0 }; + char digest_str[MAX_DIGEST_SIZE * 2 + 1] = { 0 }; + int len, cmd_len; + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/file", + commands_str[DIGEST_CACHE_GET], self->base_dir); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + /* + * If a directory digest cache was requested, we need to do a lookup, + * to make the kernel module retrieve verification data from the digest + * cache of the directory entry. + */ + if (check_dir) { + *(u32 *)digest = num; + + bin2hex(digest_str, digest, hash_digest_size[algo]); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/file|%s:%s", + commands_str[DIGEST_CACHE_LOOKUP], + self->base_dir, hash_algo_name[algo], + digest_str); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + } + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s", + commands_str[DIGEST_CACHE_SET_VERIF], + verifs_str[VERIF_FILENAMES]); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + ASSERT_LT(0, read(self->kernfd, digest_list_filename_kernel, + sizeof(digest_list_filename_kernel))); + ASSERT_EQ(0, strcmp(digest_list_filename, digest_list_filename_kernel)); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s", + commands_str[DIGEST_CACHE_SET_VERIF], + verifs_str[VERIF_NUMBER]); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + len = read(self->kernfd, number, sizeof(number) - 1); + ASSERT_LT(0, len); + number[len] = '\0'; + ASSERT_EQ(num, atoi(number)); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s", + commands_str[DIGEST_CACHE_PUT]); + write(self->kernfd, cmd, cmd_len); +} + +static void check_verif_data(struct _test_data_shared_data *self, + struct __test_metadata *_metadata) +{ + char digest_list_filename[NAME_MAX + 1]; + char cmd[1024]; + int i, cmd_len; + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s", + commands_str[DIGEST_CACHE_ENABLE_VERIF], + verifs_str[VERIF_FILENAMES]); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s", + commands_str[DIGEST_CACHE_ENABLE_VERIF], + verifs_str[VERIF_NUMBER]); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + /* + * Reverse order is intentional, so that directory entries are created + * in the opposite order as when they are searched (when prefetching is + * requested). + */ + for (i = 10; i >= 0; i--) { + snprintf(digest_list_filename, sizeof(digest_list_filename), + "%d-tlv-digest_list%d", i, i); + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, + digest_list_filename, HASH_ALGO_SHA1, + i, 1, TLV_NO_FAILURE)); + + ASSERT_EQ(0, create_file(self->base_dirfd, "file", + digest_list_filename)); + + _check_verif_data(self, _metadata, digest_list_filename, i, + HASH_ALGO_SHA1, false); + + ASSERT_EQ(0, unlinkat(self->base_dirfd, "file", 0)); + } + + for (i = 0; i < 11; i++) { + ASSERT_EQ(0, create_file(self->base_dirfd, "file", NULL)); + snprintf(digest_list_filename, sizeof(digest_list_filename), + "%d-tlv-digest_list%d", i, i); + _check_verif_data(self, _metadata, digest_list_filename, i, + HASH_ALGO_SHA1, true); + ASSERT_EQ(0, unlinkat(self->base_dirfd, "file", 0)); + } +} + +/* + * Verify that the correct verification data can be retrieved from the digest + * caches (without digest list prefetching). + */ +TEST_F(shared_data, verif_data_no_prefetch) +{ + if (self->no_kprobe) + SKIP(return, "CONFIG_DYNAMIC_FTRACE_WITH_ARGS not enabled"); + + check_verif_data(self, _metadata); +} + +/* + * Verify that the correct verification data can be retrieved from the digest + * caches (with digest list prefetching). + */ +TEST_F(shared_data, verif_data_prefetch) +{ + if (self->no_kprobe) + SKIP(return, "CONFIG_DYNAMIC_FTRACE_WITH_ARGS not enabled"); + + ASSERT_EQ(0, lsetxattr(self->base_dir, XATTR_NAME_DIG_PREFETCH, + "1", 1, 0)); + + check_verif_data(self, _metadata); +} + +static void check_prefetch_list(struct _test_data_shared_data *self, + struct __test_metadata *_metadata, + int start_number, int end_number) +{ + char digest_list_filename[NAME_MAX + 1], filename[NAME_MAX + 1]; + char digest_lists[1024] = { 0 }, digest_lists_kernel[1024]; + char cmd[1024]; + int i, cmd_len; + + snprintf(filename, sizeof(filename), "file%d", end_number); + snprintf(digest_list_filename, sizeof(digest_list_filename), + "%d-tlv-digest_list%d", end_number, end_number); + ASSERT_EQ(0, create_file(self->base_dirfd, filename, + digest_list_filename)); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/%s", + commands_str[DIGEST_CACHE_GET], self->base_dir, + filename); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + ASSERT_LT(0, read(self->kernfd, digest_lists_kernel, + sizeof(digest_lists_kernel))); + + for (i = start_number; i <= end_number; i++) { + if (digest_lists[0]) + strcat(digest_lists, ","); + + snprintf(digest_list_filename, sizeof(digest_list_filename), + "%d-tlv-digest_list%d", i, i); + strcat(digest_lists, digest_list_filename); + } + + ASSERT_EQ(0, strcmp(digest_lists, digest_lists_kernel)); + + ASSERT_EQ(0, unlinkat(self->base_dirfd, filename, 0)); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s", + commands_str[DIGEST_CACHE_PUT]); + write(self->kernfd, cmd, cmd_len); +} + +static void check_prefetch_list_async(struct _test_data_shared_data *self, + struct __test_metadata *_metadata) +{ + char digest_list_filename[NAME_MAX + 1], filename[NAME_MAX + 1]; + char digest_lists[1024] = { 0 }, digest_lists_kernel[1024]; + char cmd[1024]; + int i, cmd_len; + + for (i = 0; i < NUM_DIGEST_LISTS_PREFETCH; i++) { + snprintf(filename, sizeof(filename), "file%d", + NUM_DIGEST_LISTS_PREFETCH - 1 - i); + snprintf(digest_list_filename, sizeof(digest_list_filename), + "%d-tlv-digest_list%d", i, i); + ASSERT_EQ(0, create_file(self->base_dirfd, filename, + digest_list_filename)); + } + + /* Do batch of get/put to test the kernel for concurrent requests. */ + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/file|%d|%d", + commands_str[DIGEST_CACHE_GET_PUT_ASYNC], + self->base_dir, 0, NUM_DIGEST_LISTS_PREFETCH - 1); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + ASSERT_LT(0, read(self->kernfd, digest_lists_kernel, + sizeof(digest_lists_kernel))); + + for (i = 0; i < NUM_DIGEST_LISTS_PREFETCH; i++) { + if (digest_lists[0]) + strcat(digest_lists, ","); + + snprintf(digest_list_filename, sizeof(digest_list_filename), + "%d-tlv-digest_list%d", i, i); + strcat(digest_lists, digest_list_filename); + } + + ASSERT_EQ(0, strcmp(digest_lists, digest_lists_kernel)); +} + +static void prepare_prefetch(struct _test_data_shared_data *self, + struct __test_metadata *_metadata) +{ + char digest_list_filename[NAME_MAX + 1]; + char cmd[1024]; + int i, cmd_len; + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s", + commands_str[DIGEST_CACHE_ENABLE_VERIF], + verifs_str[VERIF_PREFETCH]); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s", + commands_str[DIGEST_CACHE_SET_VERIF], + verifs_str[VERIF_PREFETCH]); + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len)); + + for (i = NUM_DIGEST_LISTS_PREFETCH - 1; i >= 0; i--) { + snprintf(digest_list_filename, sizeof(digest_list_filename), + "%d-tlv-digest_list%d", i, i); + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, + digest_list_filename, HASH_ALGO_SHA1, + i, 1, TLV_NO_FAILURE)); + } + + ASSERT_EQ(0, fsetxattr(self->digest_lists_dirfd, + XATTR_NAME_DIG_PREFETCH, "1", 1, 0)); +} + +/* + * Verify that digest lists are prefetched when requested, in the correct order + * (synchronous version). + */ +TEST_F(shared_data, prefetch_sync) +{ + int i; + + if (self->no_kprobe) + SKIP(return, "CONFIG_DYNAMIC_FTRACE_WITH_ARGS not enabled"); + + prepare_prefetch(self, _metadata); + + for (i = 2; i < NUM_DIGEST_LISTS_PREFETCH; i += 3) + check_prefetch_list(self, _metadata, i - 2, i); +} + +/* + * Verify that digest lists are prefetched when requested, in the correct order + * (asynchronous version). + */ +TEST_F(shared_data, prefetch_async) +{ + if (self->no_kprobe) + SKIP(return, "CONFIG_DYNAMIC_FTRACE_WITH_ARGS not enabled"); + + prepare_prefetch(self, _metadata); + + check_prefetch_list_async(self, _metadata); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/digest_cache/common.c b/tools/testing/selftests/digest_cache/common.c new file mode 100644 index 000000000000..75c0ef50deb8 --- /dev/null +++ b/tools/testing/selftests/digest_cache/common.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Add common code for testing the Integrity Digest Cache. + */ + +#include "common.h" + +const char *commands_str[DIGEST_CACHE__LAST] = { + [DIGEST_CACHE_GET] = "get", + [DIGEST_CACHE_LOOKUP] = "lookup", + [DIGEST_CACHE_PUT] = "put", + [DIGEST_CACHE_ENABLE_VERIF] = "enable_verif", + [DIGEST_CACHE_DISABLE_VERIF] = "disable_verif", + [DIGEST_CACHE_SET_VERIF] = "set_verif", + [DIGEST_CACHE_GET_PUT_ASYNC] = "get_put_async", +}; + +const char *const hash_algo_name[HASH_ALGO__LAST] = { + [HASH_ALGO_MD4] = "md4", + [HASH_ALGO_MD5] = "md5", + [HASH_ALGO_SHA1] = "sha1", + [HASH_ALGO_RIPE_MD_160] = "rmd160", + [HASH_ALGO_SHA256] = "sha256", + [HASH_ALGO_SHA384] = "sha384", + [HASH_ALGO_SHA512] = "sha512", + [HASH_ALGO_SHA224] = "sha224", + [HASH_ALGO_RIPE_MD_128] = "rmd128", + [HASH_ALGO_RIPE_MD_256] = "rmd256", + [HASH_ALGO_RIPE_MD_320] = "rmd320", + [HASH_ALGO_WP_256] = "wp256", + [HASH_ALGO_WP_384] = "wp384", + [HASH_ALGO_WP_512] = "wp512", + [HASH_ALGO_TGR_128] = "tgr128", + [HASH_ALGO_TGR_160] = "tgr160", + [HASH_ALGO_TGR_192] = "tgr192", + [HASH_ALGO_SM3_256] = "sm3", + [HASH_ALGO_STREEBOG_256] = "streebog256", + [HASH_ALGO_STREEBOG_512] = "streebog512", + [HASH_ALGO_SHA3_256] = "sha3-256", + [HASH_ALGO_SHA3_384] = "sha3-384", + [HASH_ALGO_SHA3_512] = "sha3-512", +}; + +const int hash_digest_size[HASH_ALGO__LAST] = { + [HASH_ALGO_MD4] = MD5_DIGEST_SIZE, + [HASH_ALGO_MD5] = MD5_DIGEST_SIZE, + [HASH_ALGO_SHA1] = SHA1_DIGEST_SIZE, + [HASH_ALGO_RIPE_MD_160] = RMD160_DIGEST_SIZE, + [HASH_ALGO_SHA256] = SHA256_DIGEST_SIZE, + [HASH_ALGO_SHA384] = SHA384_DIGEST_SIZE, + [HASH_ALGO_SHA512] = SHA512_DIGEST_SIZE, + [HASH_ALGO_SHA224] = SHA224_DIGEST_SIZE, + [HASH_ALGO_RIPE_MD_128] = RMD128_DIGEST_SIZE, + [HASH_ALGO_RIPE_MD_256] = RMD256_DIGEST_SIZE, + [HASH_ALGO_RIPE_MD_320] = RMD320_DIGEST_SIZE, + [HASH_ALGO_WP_256] = WP256_DIGEST_SIZE, + [HASH_ALGO_WP_384] = WP384_DIGEST_SIZE, + [HASH_ALGO_WP_512] = WP512_DIGEST_SIZE, + [HASH_ALGO_TGR_128] = TGR128_DIGEST_SIZE, + [HASH_ALGO_TGR_160] = TGR160_DIGEST_SIZE, + [HASH_ALGO_TGR_192] = TGR192_DIGEST_SIZE, + [HASH_ALGO_SM3_256] = SM3256_DIGEST_SIZE, + [HASH_ALGO_STREEBOG_256] = STREEBOG256_DIGEST_SIZE, + [HASH_ALGO_STREEBOG_512] = STREEBOG512_DIGEST_SIZE, + [HASH_ALGO_SHA3_256] = SHA3_256_DIGEST_SIZE, + [HASH_ALGO_SHA3_384] = SHA3_384_DIGEST_SIZE, + [HASH_ALGO_SHA3_512] = SHA3_512_DIGEST_SIZE, +}; + +const char *verifs_str[] = { + [VERIF_FILENAMES] = "kprobe_filenames", + [VERIF_NUMBER] = "kprobe_number", + [VERIF_PREFETCH] = "kprobe_prefetch", +}; diff --git a/tools/testing/selftests/digest_cache/common.h b/tools/testing/selftests/digest_cache/common.h new file mode 100644 index 000000000000..3fd3c249ff6f --- /dev/null +++ b/tools/testing/selftests/digest_cache/common.h @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Header of common.c. + */ + +#ifndef _COMMON_H +#define _COMMON_H +#include <linux/types.h> + +#include "../../../../include/uapi/linux/hash_info.h" + +#define MD5_DIGEST_SIZE 16 +#define SHA1_DIGEST_SIZE 20 +#define RMD160_DIGEST_SIZE 20 +#define SHA256_DIGEST_SIZE 32 +#define SHA384_DIGEST_SIZE 48 +#define SHA512_DIGEST_SIZE 64 +#define SHA224_DIGEST_SIZE 28 +#define RMD128_DIGEST_SIZE 16 +#define RMD256_DIGEST_SIZE 32 +#define RMD320_DIGEST_SIZE 40 +#define WP256_DIGEST_SIZE 32 +#define WP384_DIGEST_SIZE 48 +#define WP512_DIGEST_SIZE 64 +#define TGR128_DIGEST_SIZE 16 +#define TGR160_DIGEST_SIZE 20 +#define TGR192_DIGEST_SIZE 24 +#define SM3256_DIGEST_SIZE 32 +#define STREEBOG256_DIGEST_SIZE 32 +#define STREEBOG512_DIGEST_SIZE 64 +#define SHA3_224_DIGEST_SIZE (224 / 8) +#define SHA3_256_DIGEST_SIZE (256 / 8) +#define SHA3_384_DIGEST_SIZE (384 / 8) +#define SHA3_512_DIGEST_SIZE (512 / 8) + +#define DIGEST_CACHE_DIR "/sys/kernel/security/integrity/digest_cache" +#define DIGEST_CACHE_TEST_INTERFACE "/sys/kernel/security/digest_cache_test" +#define DIGEST_CACHE_PATH_INTERFACE DIGEST_CACHE_DIR "/default_path" +#define MAX_DIGEST_SIZE 64 + +#define MAX_WORKS 21 + +typedef __u8 u8; +typedef __u16 u16; +typedef __u32 u32; +typedef __s32 s32; +typedef __u64 u64; + +enum commands { + DIGEST_CACHE_GET, // args: <path> + DIGEST_CACHE_LOOKUP, // args: <algo>|<digest> + DIGEST_CACHE_PUT, // args: + DIGEST_CACHE_ENABLE_VERIF, // args: <verif name> + DIGEST_CACHE_DISABLE_VERIF, // args: <verif name> + DIGEST_CACHE_SET_VERIF, // args: <verif name> + DIGEST_CACHE_GET_PUT_ASYNC, // args: <path>|<start#>|<end#> + DIGEST_CACHE__LAST, +}; + +enum tlv_failures { TLV_NO_FAILURE, + TLV_FAILURE_ALGO_LEN, + TLV_FAILURE_ALGO_MISMATCH, + TLV_FAILURE_NUM_DIGESTS, + TLV_FAILURE__LAST +}; + +enum file_changes { FILE_WRITE, + FILE_TRUNCATE, + FILE_FTRUNCATE, + FILE_UNLINK, + FILE_RENAME, + FILE_SETXATTR, + FILE_REMOVEXATTR, + FILE_CHANGE__LAST +}; + +enum VERIFS { + VERIF_FILENAMES, + VERIF_NUMBER, + VERIF_PREFETCH, + VERIF__LAST +}; + +extern const char *commands_str[DIGEST_CACHE__LAST]; +extern const char *const hash_algo_name[HASH_ALGO__LAST]; +extern const int hash_digest_size[HASH_ALGO__LAST]; +extern const char *verifs_str[VERIF__LAST]; + +#endif /* _COMMON_H */ diff --git a/tools/testing/selftests/digest_cache/common_user.c b/tools/testing/selftests/digest_cache/common_user.c new file mode 100644 index 000000000000..02f661b942f7 --- /dev/null +++ b/tools/testing/selftests/digest_cache/common_user.c @@ -0,0 +1,33 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Add common code in user space for testing the Integrity Digest Cache. + */ + +#include <stddef.h> + +#include "common_user.h" + +static const char hex_asc[] = "0123456789abcdef"; + +#define hex_asc_lo(x) hex_asc[((x) & 0x0f)] +#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] + +static inline char *hex_byte_pack(char *buf, unsigned char byte) +{ + *buf++ = hex_asc_hi(byte); + *buf++ = hex_asc_lo(byte); + return buf; +} + +char *bin2hex(char *dst, const void *src, size_t count) +{ + const unsigned char *_src = src; + + while (count--) + dst = hex_byte_pack(dst, *_src++); + return dst; +} diff --git a/tools/testing/selftests/digest_cache/common_user.h b/tools/testing/selftests/digest_cache/common_user.h new file mode 100644 index 000000000000..8d1f6631ef83 --- /dev/null +++ b/tools/testing/selftests/digest_cache/common_user.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Header of common_user.c. + */ + +#include <linux/types.h> +#include <stddef.h> + +#include "common.h" + +char *bin2hex(char *dst, const void *src, size_t count); diff --git a/tools/testing/selftests/digest_cache/config b/tools/testing/selftests/digest_cache/config new file mode 100644 index 000000000000..7e0ea7d18828 --- /dev/null +++ b/tools/testing/selftests/digest_cache/config @@ -0,0 +1,2 @@ +CONFIG_INTEGRITY_DIGEST_CACHE=y +CONFIG_DYNAMIC_FTRACE=y diff --git a/tools/testing/selftests/digest_cache/generators.c b/tools/testing/selftests/digest_cache/generators.c new file mode 100644 index 000000000000..8c36c22e8bcc --- /dev/null +++ b/tools/testing/selftests/digest_cache/generators.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Generate digest lists for testing. + */ + +#include <stddef.h> +#include <fcntl.h> +#include <errno.h> +#include <limits.h> +#include <string.h> +#include <unistd.h> +#include <sys/xattr.h> +#include <asm/byteorder.h> + +#include "generators.h" +#include "../../../../include/uapi/linux/hash_info.h" +#include "../../../../include/uapi/linux/xattr.h" +#include "../../../../include/uapi/linux/tlv_digest_list.h" +#include "../../../../include/uapi/linux/tlv_parser.h" + +int gen_tlv_list(int temp_dirfd, char *digest_list_filename, + enum hash_algo algo, int start_number, int num_digests, + enum tlv_failures failure) +{ + __u16 _algo = __cpu_to_be16(algo); + __u32 _num_entries = __cpu_to_be32(num_digests); + u8 digest[MAX_DIGEST_SIZE] = { 0 }; + int digest_len = hash_digest_size[algo]; + int ret, fd, i; + + struct tlv_entry algo_entry = { + .field = __cpu_to_be16(DIGEST_LIST_ALGO), + .length = __cpu_to_be32(sizeof(_algo)), + }; + + struct tlv_entry num_entries_entry = { + .field = __cpu_to_be16(DIGEST_LIST_NUM_ENTRIES), + .length = __cpu_to_be32(sizeof(_num_entries)), + }; + + struct tlv_entry entry_digest = { + .field = __cpu_to_be16(DIGEST_LIST_ENTRY_DIGEST), + .length = __cpu_to_be32(digest_len), + }; + + struct tlv_entry entry_entry = { + .field = __cpu_to_be16(DIGEST_LIST_ENTRY), + .length = __cpu_to_be32(sizeof(entry_digest) + digest_len), + }; + + switch (failure) { + case TLV_FAILURE_ALGO_LEN: + algo_entry.length = algo_entry.length / 2; + break; + case TLV_FAILURE_ALGO_MISMATCH: + _algo = __cpu_to_be16(algo - 1); + break; + case TLV_FAILURE_NUM_DIGESTS: + num_digests = 0; + break; + default: + break; + } + + fd = openat(temp_dirfd, digest_list_filename, + O_WRONLY | O_CREAT | O_TRUNC, 0600); + if (fd == -1) + return -errno; + + ret = write(fd, (u8 *)&algo_entry, sizeof(algo_entry)); + if (ret != sizeof(algo_entry)) + return -errno; + + ret = write(fd, (u8 *)&_algo, sizeof(_algo)); + if (ret != sizeof(_algo)) + return -errno; + + ret = write(fd, (u8 *)&num_entries_entry, sizeof(num_entries_entry)); + if (ret != sizeof(num_entries_entry)) + return -errno; + + ret = write(fd, (u8 *)&_num_entries, sizeof(_num_entries)); + if (ret != sizeof(_num_entries)) + return -errno; + + *(u32 *)digest = start_number; + + for (i = 0; i < num_digests; i++) { + ret = write(fd, (u8 *)&entry_entry, sizeof(entry_entry)); + if (ret != sizeof(entry_entry)) + return -errno; + + ret = write(fd, (u8 *)&entry_digest, sizeof(entry_digest)); + if (ret != sizeof(entry_digest)) + return -errno; + + ret = write(fd, digest, digest_len); + if (ret != digest_len) + return -errno; + + (*(u32 *)digest)++; + } + + close(fd); + return 0; +} + +int create_file(int temp_dirfd, char *filename, char *digest_list_filename) +{ + int ret = 0, fd; + + fd = openat(temp_dirfd, filename, O_WRONLY | O_CREAT | O_TRUNC, 0600); + if (fd == -1) + return -errno; + + if (!digest_list_filename) + goto out; + + ret = fsetxattr(fd, XATTR_NAME_DIGEST_LIST, digest_list_filename, + strlen(digest_list_filename) + 1, 0); + if (ret == -1) + ret = -errno; +out: + close(fd); + return ret; +} diff --git a/tools/testing/selftests/digest_cache/generators.h b/tools/testing/selftests/digest_cache/generators.h new file mode 100644 index 000000000000..eeeb3c020891 --- /dev/null +++ b/tools/testing/selftests/digest_cache/generators.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Header of generators.c. + */ + +#include "common.h" +#include "common_user.h" + +int gen_tlv_list(int temp_dirfd, char *digest_list_filename, + enum hash_algo algo, int start_number, int num_digests, + enum tlv_failures failure); +int create_file(int temp_dirfd, char *filename, char *digest_list_filename); diff --git a/tools/testing/selftests/digest_cache/testmod/Makefile b/tools/testing/selftests/digest_cache/testmod/Makefile new file mode 100644 index 000000000000..1ba1c7f08658 --- /dev/null +++ b/tools/testing/selftests/digest_cache/testmod/Makefile @@ -0,0 +1,16 @@ +KDIR ?= ../../../../.. + +MODULES = digest_cache_kern.ko + +obj-m += digest_cache_kern.o + +digest_cache_kern-y := kern.o ../common.o + +all: + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD modules + +clean: + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD clean + +install: all + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD modules_install diff --git a/tools/testing/selftests/digest_cache/testmod/kern.c b/tools/testing/selftests/digest_cache/testmod/kern.c new file mode 100644 index 000000000000..4c215fd0b50f --- /dev/null +++ b/tools/testing/selftests/digest_cache/testmod/kern.c @@ -0,0 +1,551 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <[email protected]> + * + * Implement the kernel module to interact with the Integrity Digest Cache. + */ + +#define pr_fmt(fmt) "digest_cache TESTMOD: "fmt +#include <linux/module.h> +#include <linux/namei.h> +#include <linux/security.h> +#include <linux/dynamic_debug.h> +#include <linux/digest_cache.h> +#include <linux/kprobes.h> +#include <linux/cpu.h> +#include <linux/kernel_read_file.h> +#include <crypto/hash_info.h> + +#include "../common.h" + +struct verif { + int (*update)(struct file *file); + ssize_t (*read)(struct file *file, char __user *buf, size_t datalen, + loff_t *ppos); + bool enabled; +}; + +struct read_work { + struct work_struct work; + char *path_str; + int ret; +}; + +static struct dentry *test; +static struct digest_cache *digest_cache, *found; +static int cur_verif_index; +static u8 prefetch_buf[4096]; +static struct read_work w[MAX_WORKS]; + +static int filenames_update(struct file *file) +{ + char *filename = (char *)file->f_path.dentry->d_name.name; + + return digest_cache_verif_set(file, verifs_str[VERIF_FILENAMES], + filename, strlen(filename) + 1); +} + +static int number_update(struct file *file) +{ + const char *filename = file_dentry(file)->d_name.name; + size_t filename_len = strlen(filename); + u64 number = U64_MAX; + int ret; + + while (filename_len) { + if (filename[filename_len - 1] < '0' || + filename[filename_len - 1] > '9') + break; + + filename_len--; + } + + ret = kstrtoull(filename + filename_len, 10, &number); + if (ret < 0) { + pr_debug("Failed to convert filename %s into number\n", + file_dentry(file)->d_name.name); + return ret; + } + + return digest_cache_verif_set(file, verifs_str[VERIF_NUMBER], &number, + sizeof(number)); +} + +static int prefetch_update(struct file *file) +{ + char *filename = (char *)file->f_path.dentry->d_name.name; + char *start_ptr = prefetch_buf, *end_ptr; + int ret; + + ret = digest_cache_verif_set(file, "kprobe_test", "1", 1); + if (!ret) { + /* Don't include duplicates of requested digest lists. */ + while ((end_ptr = strchrnul(start_ptr, ','))) { + if (end_ptr > start_ptr && + !strncmp(start_ptr, filename, end_ptr - start_ptr)) + return 0; + + if (!*end_ptr) + break; + + start_ptr = end_ptr + 1; + } + } + + if (prefetch_buf[0]) + strlcat(prefetch_buf, ",", sizeof(prefetch_buf)); + + strlcat(prefetch_buf, filename, sizeof(prefetch_buf)); + return 0; +} + +static ssize_t filenames_read(struct file *file, char __user *buf, + size_t datalen, loff_t *ppos) +{ + loff_t _ppos = 0; + char *filenames_list; + + filenames_list = digest_cache_verif_get(found ?: digest_cache, + verifs_str[VERIF_FILENAMES]); + if (!filenames_list) + return -ENOENT; + + return simple_read_from_buffer(buf, datalen, &_ppos, filenames_list, + strlen(filenames_list) + 1); +} + +static ssize_t number_read(struct file *file, char __user *buf, size_t datalen, + loff_t *ppos) +{ + loff_t _ppos = 0; + u64 *number; + char temp[20]; + ssize_t len; + + number = digest_cache_verif_get(found ?: digest_cache, + verifs_str[VERIF_NUMBER]); + if (!number) + return -ENOENT; + + len = snprintf(temp, sizeof(temp), "%llu", *number); + + return simple_read_from_buffer(buf, datalen, &_ppos, temp, len); +} + +static ssize_t prefetch_read(struct file *file, char __user *buf, + size_t datalen, loff_t *ppos) +{ + loff_t _ppos = 0; + ssize_t ret; + + ret = simple_read_from_buffer(buf, datalen, &_ppos, prefetch_buf, + strlen(prefetch_buf) + 1); + memset(prefetch_buf, 0, sizeof(prefetch_buf)); + return ret; +} + +static struct verif verifs_methods[] = { + [VERIF_FILENAMES] = { .update = filenames_update, + .read = filenames_read }, + [VERIF_NUMBER] = { .update = number_update, .read = number_read }, + [VERIF_PREFETCH] = { .update = prefetch_update, .read = prefetch_read }, +}; + +static void digest_cache_get_put_work(struct work_struct *work) +{ + struct read_work *w = container_of(work, struct read_work, work); + struct digest_cache *digest_cache; + struct path path; + struct file *file; + + w->ret = kern_path(w->path_str, 0, &path); + if (w->ret < 0) + return; + + file = kernel_file_open(&path, O_RDONLY, current_cred()); + if (IS_ERR(file)) { + path_put(&path); + return; + } + + digest_cache = digest_cache_get(file); + + fput(file); + path_put(&path); + + if (!digest_cache) { + w->ret = -ENOENT; + return; + } + + digest_cache_put(digest_cache); + w->ret = 0; +} + +static int digest_cache_get_put_async(char *path_str, int start_number, + int end_number) +{ + int ret = 0, i; + + cpus_read_lock(); + for (i = start_number; i <= end_number; i++) { + w[i].path_str = kasprintf(GFP_KERNEL, "%s%u", path_str, i); + if (!w[i].path_str) { + ret = -ENOMEM; + break; + } + + INIT_WORK_ONSTACK(&w[i].work, digest_cache_get_put_work); + schedule_work_on(i % num_online_cpus(), &w[i].work); + } + cpus_read_unlock(); + + for (i = start_number; i <= end_number; i++) { + if (!w[i].path_str) + continue; + + flush_work(&w[i].work); + destroy_work_on_stack(&w[i].work); + kfree(w[i].path_str); + w[i].path_str = NULL; + if (!ret) + ret = w[i].ret; + } + + return ret; +} + +static ssize_t write_request(struct file *file, const char __user *buf, + size_t datalen, loff_t *ppos) +{ + char *data, *data_ptr, *cmd_str, *path_str, *algo_str, *digest_str; + char *verif_name_str, *start_number_str, *end_number_str; + u8 digest[64]; + struct path path; + struct file *filp; + int ret, cmd, algo, verif_index, start_number, end_number; + + data = memdup_user_nul(buf, datalen); + if (IS_ERR(data)) + return PTR_ERR(data); + + data_ptr = data; + + cmd_str = strsep(&data_ptr, "|"); + if (!cmd_str) { + pr_debug("No command\n"); + ret = -EINVAL; + goto out; + } + + cmd = match_string(commands_str, DIGEST_CACHE__LAST, cmd_str); + if (cmd < 0) { + pr_err("Unknown command %s\n", cmd_str); + ret = -ENOENT; + goto out; + } + + switch (cmd) { + case DIGEST_CACHE_GET: + if (found) { + if (!IS_ERR(found)) + digest_cache_put(found); + + found = NULL; + } + + path_str = strsep(&data_ptr, "|"); + if (!path_str) { + pr_debug("No path\n"); + ret = -EINVAL; + goto out; + } + + ret = kern_path(path_str, 0, &path); + if (ret < 0) { + pr_debug("Cannot find file %s\n", path_str); + goto out; + } + + if (digest_cache) { + pr_debug("Digest cache exists, doing a put\n"); + digest_cache_put(digest_cache); + } + + filp = kernel_file_open(&path, O_RDONLY, current_cred()); + if (IS_ERR(filp)) { + pr_debug("Cannot open file %s\n", path_str); + path_put(&path); + goto out; + } + + digest_cache = digest_cache_get(filp); + ret = digest_cache ? 0 : -ENOENT; + pr_debug("digest cache get %s, ret: %d\n", path_str, ret); + fput(filp); + path_put(&path); + break; + case DIGEST_CACHE_LOOKUP: + if (found) { + if (!IS_ERR(found)) + digest_cache_put(found); + + found = NULL; + } + + if (!digest_cache) { + pr_debug("No digest cache\n"); + ret = -ENOENT; + goto out; + } + + path_str = strsep(&data_ptr, "|"); + if (!path_str) { + pr_debug("No path\n"); + ret = -EINVAL; + goto out; + } + + algo_str = strsep(&data_ptr, ":"); + digest_str = data_ptr; + + if (!algo_str || !digest_str) { + pr_debug("No algo or digest\n"); + ret = -EINVAL; + goto out; + } + + algo = match_string(hash_algo_name, HASH_ALGO__LAST, algo_str); + if (algo < 0) { + pr_err("Unknown algorithm %s", algo_str); + ret = -ENOENT; + goto out; + } + + ret = hex2bin(digest, digest_str, hash_digest_size[algo]); + if (ret < 0) { + pr_debug("Invalid digest %s\n", digest_str); + goto out; + } + + ret = kern_path(path_str, 0, &path); + if (ret < 0) { + pr_debug("Cannot find file %s\n", path_str); + goto out; + } + + ret = -ENOENT; + + found = digest_cache_lookup(path.dentry, digest_cache, digest, + algo); + path_put(&path); + if (found && !IS_ERR(found)) + ret = 0; + + pr_debug("%s:%s lookup %s, ret: %d\n", algo_str, digest_str, + path_str, ret); + break; + case DIGEST_CACHE_PUT: + if (digest_cache) { + digest_cache_put(digest_cache); + digest_cache = NULL; + } + + if (found) { + if (!IS_ERR(found)) + digest_cache_put(found); + + found = NULL; + } + ret = 0; + pr_debug("digest cache put, ret: %d\n", ret); + break; + case DIGEST_CACHE_ENABLE_VERIF: + case DIGEST_CACHE_DISABLE_VERIF: + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)) { + ret = -EOPNOTSUPP; + goto out; + } + + memset(prefetch_buf, 0, sizeof(prefetch_buf)); + fallthrough; + case DIGEST_CACHE_SET_VERIF: + verif_name_str = strsep(&data_ptr, "|"); + if (!verif_name_str) { + pr_debug("No verifier name\n"); + ret = -EINVAL; + goto out; + } + + verif_index = match_string(verifs_str, ARRAY_SIZE(verifs_str), + verif_name_str); + if (verif_index < 0) { + pr_err("Unknown verifier name %s\n", verif_name_str); + ret = -ENOENT; + goto out; + } + + if (cmd == DIGEST_CACHE_ENABLE_VERIF) + verifs_methods[verif_index].enabled = true; + else if (cmd == DIGEST_CACHE_DISABLE_VERIF) + verifs_methods[verif_index].enabled = false; + else + cur_verif_index = verif_index; + + ret = 0; + pr_debug("digest cache %s %s, ret: %d\n", cmd_str, + verif_name_str, ret); + break; + case DIGEST_CACHE_GET_PUT_ASYNC: + path_str = strsep(&data_ptr, "|"); + if (!path_str) { + pr_debug("No path\n"); + ret = -EINVAL; + goto out; + } + + start_number_str = strsep(&data_ptr, "|"); + if (!start_number_str) { + pr_debug("No start number\n"); + ret = -EINVAL; + goto out; + } + + ret = kstrtoint(start_number_str, 10, &start_number); + if (ret < 0) { + pr_debug("Invalid start number %s\n", start_number_str); + ret = -EINVAL; + goto out; + } + + end_number_str = strsep(&data_ptr, "|"); + if (!end_number_str) { + pr_debug("No end number\n"); + ret = -EINVAL; + goto out; + } + + ret = kstrtoint(end_number_str, 10, &end_number); + if (ret < 0) { + pr_debug("Invalid end number %s\n", end_number_str); + ret = -EINVAL; + goto out; + } + + if (end_number - start_number >= MAX_WORKS) { + pr_debug("Too many works (%d), max %d\n", + end_number - start_number, MAX_WORKS - 1); + ret = -EINVAL; + goto out; + } + + ret = digest_cache_get_put_async(path_str, start_number, + end_number); + pr_debug("digest cache %s on %s, start: %d, end: %d, ret: %d\n", + cmd_str, path_str, start_number, end_number, ret); + break; + default: + ret = -EINVAL; + break; + } +out: + kfree(data); + return ret ?: datalen; +} + +static ssize_t read_request(struct file *file, char __user *buf, size_t datalen, + loff_t *ppos) +{ + return verifs_methods[cur_verif_index].read(file, buf, datalen, ppos); +} + +static const struct file_operations digest_cache_test_ops = { + .open = generic_file_open, + .write = write_request, + .read = read_request, + .llseek = generic_file_llseek, +}; + +static int __kprobes kernel_post_read_file_hook(struct kprobe *p, + struct pt_regs *regs) +{ +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS + struct file *file = (struct file *)regs_get_kernel_argument(regs, 0); + enum kernel_read_file_id id = regs_get_kernel_argument(regs, 3); +#else + struct file *file = NULL; + enum kernel_read_file_id id = READING_UNKNOWN; +#endif + int ret, i; + + if (id != READING_DIGEST_LIST) + return 0; + + for (i = 0; i < ARRAY_SIZE(verifs_methods); i++) { + if (!verifs_methods[i].enabled) + continue; + + ret = verifs_methods[i].update(file); + if (ret < 0) + return 0; + } + + return 0; +} + +static struct kprobe kp = { + .symbol_name = "security_kernel_post_read_file", +}; + +static int __init digest_cache_test_init(void) +{ + int ret; + + kp.pre_handler = kernel_post_read_file_hook; + + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)) { + ret = register_kprobe(&kp); + if (ret < 0) { + pr_err("register_kprobe failed, returned %d\n", ret); + return ret; + } + } + + test = securityfs_create_file("digest_cache_test", 0660, NULL, NULL, + &digest_cache_test_ops); + if (IS_ERR(test)) { + ret = PTR_ERR(test); + goto out_kprobe; + } + + return 0; +out_kprobe: + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)) + unregister_kprobe(&kp); + return ret; +} + +static void __exit digest_cache_test_fini(void) +{ + if (digest_cache) + digest_cache_put(digest_cache); + + if (found) { + if (!IS_ERR(found)) + digest_cache_put(found); + + found = NULL; + } + + securityfs_remove(test); + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)) + unregister_kprobe(&kp); + pr_debug("kprobe at %p unregistered\n", kp.addr); +} + +module_init(digest_cache_test_init); +module_exit(digest_cache_test_fini); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Kernel module for testing Integrity Digest Cache"); -- 2.47.0.118.gfd3785337b
