Exercises Landlock's IOCTL feature in different combinations of handling and permitting the rights LANDLOCK_ACCESS_FS_IOCTL, LANDLOCK_ACCESS_FS_READ_FILE, LANDLOCK_ACCESS_FS_WRITE_FILE and LANDLOCK_ACCESS_FS_READ_DIR, and in different combinations of using files and directories. Signed-off-by: Günther Noack <gnoack@xxxxxxxxxx> --- tools/testing/selftests/landlock/fs_test.c | 379 ++++++++++++++++++++- 1 file changed, 376 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index 3203f4a5bc85..6ff1026c26c2 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -23,6 +23,12 @@ #include <sys/vfs.h> #include <unistd.h> +/* + * Intentionally included last to work around header conflict. + * See https://sourceware.org/glibc/wiki/Synchronizing_Headers. + */ +#include <linux/fs.h> + #include "common.h" #ifndef renameat2 @@ -735,6 +741,9 @@ static int create_ruleset(struct __test_metadata *const _metadata, } for (i = 0; rules[i].path; i++) { + if (!rules[i].access) + continue; + add_path_beneath(_metadata, ruleset_fd, rules[i].access, rules[i].path); } @@ -3443,7 +3452,7 @@ TEST_F_FORK(layout1, truncate_unhandled) LANDLOCK_ACCESS_FS_WRITE_FILE; int ruleset_fd; - /* Enable Landlock. */ + /* Enables Landlock. */ ruleset_fd = create_ruleset(_metadata, handled, rules); ASSERT_LE(0, ruleset_fd); @@ -3526,7 +3535,7 @@ TEST_F_FORK(layout1, truncate) LANDLOCK_ACCESS_FS_TRUNCATE; int ruleset_fd; - /* Enable Landlock. */ + /* Enables Landlock. */ ruleset_fd = create_ruleset(_metadata, handled, rules); ASSERT_LE(0, ruleset_fd); @@ -3752,7 +3761,7 @@ TEST_F_FORK(ftruncate, open_and_ftruncate) }; int fd, ruleset_fd; - /* Enable Landlock. */ + /* Enables Landlock. */ ruleset_fd = create_ruleset(_metadata, variant->handled, rules); ASSERT_LE(0, ruleset_fd); enforce_ruleset(_metadata, ruleset_fd); @@ -3829,6 +3838,16 @@ TEST_F_FORK(ftruncate, open_and_ftruncate_in_different_processes) ASSERT_EQ(0, close(socket_fds[1])); } +/* Invokes the FS_IOC_GETFLAGS IOCTL and returns its errno or 0. */ +static int test_fs_ioc_getflags_ioctl(int fd) +{ + uint32_t flags; + + if (ioctl(fd, FS_IOC_GETFLAGS, &flags) < 0) + return errno; + return 0; +} + TEST(memfd_ftruncate) { int fd; @@ -3845,6 +3864,360 @@ TEST(memfd_ftruncate) ASSERT_EQ(0, close(fd)); } +/* clang-format off */ +FIXTURE(ioctl) {}; +/* clang-format on */ + +FIXTURE_SETUP(ioctl) +{ + prepare_layout(_metadata); + create_file(_metadata, file1_s1d1); +} + +FIXTURE_TEARDOWN(ioctl) +{ + EXPECT_EQ(0, remove_path(file1_s1d1)); + cleanup_layout(_metadata); +} + +FIXTURE_VARIANT(ioctl) +{ + const __u64 handled; + const __u64 allowed; + const mode_t open_mode; + /* + * These are the expected IOCTL results for a representative IOCTL from + * each of the IOCTL groups. We only distinguish the 0 and EACCES + * results here, and treat other errors as 0. + */ + const int expected_fioqsize_result; /* RW */ + const int expected_fibmap_result; /* RW_FILE */ + const int expected_fionread_result; /* special */ +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_none) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_IOCTL, + .allowed = 0, + .open_mode = O_RDWR, + /* + * If LANDLOCK_ACCESS_FS_IOCTL is handled, but nothing else is + * explicitly handled, almost all IOCTL commands will be governed by the + * LANDLOCK_ACCESS_FS_IOCTL right. Files can be opened, but IOCTLs are + * disallowed. + */ + .expected_fioqsize_result = EACCES, + .expected_fibmap_result = EACCES, + .expected_fionread_result = EACCES, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_i) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_IOCTL, + .open_mode = O_RDWR, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, unhandled) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_EXECUTE, + .allowed = LANDLOCK_ACCESS_FS_EXECUTE, + .open_mode = O_RDWR, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_rwd_allowed_r) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_READ_DIR, + .allowed = LANDLOCK_ACCESS_FS_READ_FILE, + .open_mode = O_RDONLY, + /* If LANDLOCK_ACCESS_FS_IOCTL is not handled, all IOCTLs work. */ + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_rwd_allowed_w) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_READ_DIR, + .allowed = LANDLOCK_ACCESS_FS_WRITE_FILE, + .open_mode = O_WRONLY, + /* If LANDLOCK_ACCESS_FS_IOCTL is not handled, all IOCTLs work. */ + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_ri_allowed_r) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_READ_FILE, + .open_mode = O_RDONLY, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_wi_allowed_w) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_WRITE_FILE, + .open_mode = O_WRONLY, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_di_allowed_d) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_DIR | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_READ_DIR, + .open_mode = O_RDWR, + .expected_fioqsize_result = 0, + .expected_fibmap_result = EACCES, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_rwi_allowed_rw) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_WRITE_FILE, + .open_mode = O_RDWR, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_rwi_allowed_r) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_READ_FILE, + .open_mode = O_RDONLY, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_rwi_allowed_ri) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .open_mode = O_RDONLY, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_rwi_allowed_w) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_WRITE_FILE, + .open_mode = O_WRONLY, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_rwi_allowed_wi) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .allowed = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_IOCTL, + .open_mode = O_WRONLY, + .expected_fioqsize_result = 0, + .expected_fibmap_result = 0, + .expected_fionread_result = 0, +}; + +static int test_fioqsize_ioctl(int fd) +{ + size_t sz; + + if (ioctl(fd, FIOQSIZE, &sz) < 0) + return errno; + return 0; +} + +static int test_fibmap_ioctl(int fd) +{ + int blk = 0; + + /* + * We only want to distinguish here whether Landlock already caught it, + * so we treat anything but EACCESS as success. (It commonly returns + * EPERM when missing CAP_SYS_RAWIO.) + */ + if (ioctl(fd, FIBMAP, &blk) < 0 && errno == EACCES) + return errno; + return 0; +} + +static int test_fionread_ioctl(int fd) +{ + size_t sz = 0; + + if (ioctl(fd, FIONREAD, &sz) < 0 && errno == EACCES) + return errno; + return 0; +} + +TEST_F_FORK(ioctl, handle_dir_access_file) +{ + const int flag = 0; + const struct rule rules[] = { + { + .path = dir_s1d1, + .access = variant->allowed, + }, + {}, + }; + int file_fd, ruleset_fd; + + /* Enables Landlock. */ + ruleset_fd = create_ruleset(_metadata, variant->handled, rules); + ASSERT_LE(0, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + file_fd = open(file1_s1d1, variant->open_mode); + ASSERT_LE(0, file_fd); + + /* + * Checks that IOCTL commands in each IOCTL group return the expected + * errors. + */ + EXPECT_EQ(variant->expected_fioqsize_result, + test_fioqsize_ioctl(file_fd)); + EXPECT_EQ(variant->expected_fibmap_result, test_fibmap_ioctl(file_fd)); + EXPECT_EQ(variant->expected_fionread_result, + test_fionread_ioctl(file_fd)); + + /* Checks that unrestrictable commands are unrestricted. */ + EXPECT_EQ(0, ioctl(file_fd, FIOCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag)); + EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag)); + + ASSERT_EQ(0, close(file_fd)); +} + +TEST_F_FORK(ioctl, handle_dir_access_dir) +{ + const char *const path = dir_s1d1; + const int flag = 0; + const struct rule rules[] = { + { + .path = path, + .access = variant->allowed, + }, + {}, + }; + int dir_fd, ruleset_fd; + + /* Enables Landlock. */ + ruleset_fd = create_ruleset(_metadata, variant->handled, rules); + ASSERT_LE(0, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + /* + * Ignore variant->open_mode for this test, as we intend to open a + * directory. If the directory can not be opened, the variant is + * infeasible to test with an opened directory. + */ + dir_fd = open(path, O_RDONLY); + if (dir_fd < 0) + return; + + /* + * Checks that IOCTL commands in each IOCTL group return the expected + * errors. + */ + EXPECT_EQ(variant->expected_fioqsize_result, + test_fioqsize_ioctl(dir_fd)); + EXPECT_EQ(variant->expected_fibmap_result, test_fibmap_ioctl(dir_fd)); + EXPECT_EQ(variant->expected_fionread_result, + test_fionread_ioctl(dir_fd)); + + /* Checks that unrestrictable commands are unrestricted. */ + EXPECT_EQ(0, ioctl(dir_fd, FIOCLEX)); + EXPECT_EQ(0, ioctl(dir_fd, FIONCLEX)); + EXPECT_EQ(0, ioctl(dir_fd, FIONBIO, &flag)); + EXPECT_EQ(0, ioctl(dir_fd, FIOASYNC, &flag)); + + ASSERT_EQ(0, close(dir_fd)); +} + +TEST_F_FORK(ioctl, handle_file_access_file) +{ + const char *const path = file1_s1d1; + const int flag = 0; + const struct rule rules[] = { + { + .path = path, + .access = variant->allowed, + }, + {}, + }; + int file_fd, ruleset_fd; + + if (variant->allowed & LANDLOCK_ACCESS_FS_READ_DIR) { + SKIP(return, "LANDLOCK_ACCESS_FS_READ_DIR " + "can not be granted on files"); + } + + /* Enables Landlock. */ + ruleset_fd = create_ruleset(_metadata, variant->handled, rules); + ASSERT_LE(0, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + file_fd = open(path, variant->open_mode); + ASSERT_LE(0, file_fd); + + /* + * Checks that IOCTL commands in each IOCTL group return the expected + * errors. + */ + EXPECT_EQ(variant->expected_fioqsize_result, + test_fioqsize_ioctl(file_fd)); + EXPECT_EQ(variant->expected_fibmap_result, test_fibmap_ioctl(file_fd)); + EXPECT_EQ(variant->expected_fionread_result, + test_fionread_ioctl(file_fd)); + + /* Checks that unrestrictable commands are unrestricted. */ + EXPECT_EQ(0, ioctl(file_fd, FIOCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag)); + EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag)); + + ASSERT_EQ(0, close(file_fd)); +} + /* clang-format off */ FIXTURE(layout1_bind) {}; /* clang-format on */ -- 2.43.0.687.g38aa6559b0-goog
