littlefs/tests/test_evil.toml

# Tests for recovering from conditions which shouldn't normally
# happen during normal operation of littlefs

# invalid pointer tests (outside of block_count)

[cases.test_evil_invalid_tail_pointer]
defines.TAIL_TYPE = ['LFS_TYPE_HARDTAIL', 'LFS_TYPE_SOFTTAIL']
defines.INVALSET = [0x3, 0x1, 0x2]
in = "lfs.c"
code = '''
    // create littlefs
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;

    // change tail-pointer to invalid pointers
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8),
                (lfs_block_t[2]){
                    (INVALSET & 0x1) ? 0xcccccccc : 0,
                    (INVALSET & 0x2) ? 0xcccccccc : 0}})) => 0;
    lfs_deinit(&lfs) => 0;

    // test that mount fails gracefully
    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
'''

[cases.test_evil_invalid_dir_pointer]
defines.INVALSET = [0x3, 0x1, 0x2]
in = "lfs.c"
code = '''
    // create littlefs
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;
    // make a dir
    lfs_mount(&lfs, cfg) => 0;
    lfs_mkdir(&lfs, "dir_here") => 0;
    lfs_unmount(&lfs) => 0;

    // change the dir pointer to be invalid
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    // make sure id 1 == our directory
    uint8_t buffer[1024];
    lfs_dir_get(&lfs, &mdir,
            LFS_MKTAG(0x700, 0x3ff, 0),
            LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("dir_here")), buffer)
                => LFS_MKTAG(LFS_TYPE_DIR, 1, strlen("dir_here"));
    assert(memcmp((char*)buffer, "dir_here", strlen("dir_here")) == 0);
    // change dir pointer
    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
            {LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, 8),
                (lfs_block_t[2]){
                    (INVALSET & 0x1) ? 0xcccccccc : 0,
                    (INVALSET & 0x2) ? 0xcccccccc : 0}})) => 0;
    lfs_deinit(&lfs) => 0;

    // test that accessing our bad dir fails, note there's a number
    // of ways to access the dir, some can fail, but some don't
    lfs_mount(&lfs, cfg) => 0;
    struct lfs_info info;
    lfs_stat(&lfs, "dir_here", &info) => 0;
    assert(strcmp(info.name, "dir_here") == 0);
    assert(info.type == LFS_TYPE_DIR);

    lfs_dir_t dir;
    lfs_dir_open(&lfs, &dir, "dir_here") => LFS_ERR_CORRUPT;
    lfs_stat(&lfs, "dir_here/file_here", &info) => LFS_ERR_CORRUPT;
    lfs_dir_open(&lfs, &dir, "dir_here/dir_here") => LFS_ERR_CORRUPT;
    lfs_file_t file;
    lfs_file_open(&lfs, &file, "dir_here/file_here",
            LFS_O_RDONLY) => LFS_ERR_CORRUPT;
    lfs_file_open(&lfs, &file, "dir_here/file_here",
            LFS_O_WRONLY | LFS_O_CREAT) => LFS_ERR_CORRUPT;
    lfs_unmount(&lfs) => 0;
'''

[cases.test_evil_invalid_file_pointer]
in = "lfs.c"
defines.SIZE = [10, 1000, 100000] # faked file size
code = '''
    // create littlefs
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;
    // make a file
    lfs_mount(&lfs, cfg) => 0;
    lfs_file_t file;
    lfs_file_open(&lfs, &file, "file_here",
            LFS_O_WRONLY | LFS_O_CREAT) => 0;
    lfs_file_close(&lfs, &file) => 0;
    lfs_unmount(&lfs) => 0;

    // change the file pointer to be invalid
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    // make sure id 1 == our file
    uint8_t buffer[1024];
    lfs_dir_get(&lfs, &mdir,
            LFS_MKTAG(0x700, 0x3ff, 0),
            LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("file_here")), buffer)
                => LFS_MKTAG(LFS_TYPE_REG, 1, strlen("file_here"));
    assert(memcmp((char*)buffer, "file_here", strlen("file_here")) == 0);
    // change file pointer
    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
            {LFS_MKTAG(LFS_TYPE_CTZSTRUCT, 1, sizeof(struct lfs_ctz)),
                &(struct lfs_ctz){0xcccccccc, lfs_tole32(SIZE)}})) => 0;
    lfs_deinit(&lfs) => 0;

    // test that accessing our bad file fails, note there's a number
    // of ways to access the dir, some can fail, but some don't
    lfs_mount(&lfs, cfg) => 0;
    struct lfs_info info;
    lfs_stat(&lfs, "file_here", &info) => 0;
    assert(strcmp(info.name, "file_here") == 0);
    assert(info.type == LFS_TYPE_REG);
    assert(info.size == SIZE);

    lfs_file_open(&lfs, &file, "file_here", LFS_O_RDONLY) => 0;
    lfs_file_read(&lfs, &file, buffer, SIZE) => LFS_ERR_CORRUPT;
    lfs_file_close(&lfs, &file) => 0;

    // any allocs that traverse CTZ must unfortunately must fail
    if (SIZE > 2*BLOCK_SIZE) {
        lfs_mkdir(&lfs, "dir_here") => LFS_ERR_CORRUPT;
    }
    lfs_unmount(&lfs) => 0;
'''

[cases.test_evil_invalid_ctz_pointer] # invalid pointer in CTZ skip-list test
defines.SIZE = ['2*BLOCK_SIZE', '3*BLOCK_SIZE', '4*BLOCK_SIZE']
in = "lfs.c"
code = '''
    // create littlefs
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;
    // make a file
    lfs_mount(&lfs, cfg) => 0;
    lfs_file_t file;
    lfs_file_open(&lfs, &file, "file_here",
            LFS_O_WRONLY | LFS_O_CREAT) => 0;
    for (int i = 0; i < SIZE; i++) {
        char c = 'c';
        lfs_file_write(&lfs, &file, &c, 1) => 1;
    }
    lfs_file_close(&lfs, &file) => 0;
    lfs_unmount(&lfs) => 0;
    // change pointer in CTZ skip-list to be invalid
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    // make sure id 1 == our file and get our CTZ structure
    uint8_t buffer[4*BLOCK_SIZE];
    lfs_dir_get(&lfs, &mdir,
            LFS_MKTAG(0x700, 0x3ff, 0),
            LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("file_here")), buffer)
                => LFS_MKTAG(LFS_TYPE_REG, 1, strlen("file_here"));
    assert(memcmp((char*)buffer, "file_here", strlen("file_here")) == 0);
    struct lfs_ctz ctz;
    lfs_dir_get(&lfs, &mdir,
            LFS_MKTAG(0x700, 0x3ff, 0),
            LFS_MKTAG(LFS_TYPE_STRUCT, 1, sizeof(struct lfs_ctz)), &ctz)
                => LFS_MKTAG(LFS_TYPE_CTZSTRUCT, 1, sizeof(struct lfs_ctz));
    lfs_ctz_fromle32(&ctz);
    // rewrite block to contain bad pointer
    uint8_t bbuffer[BLOCK_SIZE];
    cfg->read(cfg, ctz.head, 0, bbuffer, BLOCK_SIZE) => 0;
    uint32_t bad = lfs_tole32(0xcccccccc);
    memcpy(&bbuffer[0], &bad, sizeof(bad));
    memcpy(&bbuffer[4], &bad, sizeof(bad));
    cfg->erase(cfg, ctz.head) => 0;
    cfg->prog(cfg, ctz.head, 0, bbuffer, BLOCK_SIZE) => 0;
    lfs_deinit(&lfs) => 0;

    // test that accessing our bad file fails, note there's a number
    // of ways to access the dir, some can fail, but some don't
    lfs_mount(&lfs, cfg) => 0;
    struct lfs_info info;
    lfs_stat(&lfs, "file_here", &info) => 0;
    assert(strcmp(info.name, "file_here") == 0);
    assert(info.type == LFS_TYPE_REG);
    assert(info.size == SIZE);

    lfs_file_open(&lfs, &file, "file_here", LFS_O_RDONLY) => 0;
    lfs_file_read(&lfs, &file, buffer, SIZE) => LFS_ERR_CORRUPT;
    lfs_file_close(&lfs, &file) => 0;

    // any allocs that traverse CTZ must unfortunately must fail
    if (SIZE > 2*BLOCK_SIZE) {
        lfs_mkdir(&lfs, "dir_here") => LFS_ERR_CORRUPT;
    }
    lfs_unmount(&lfs) => 0;
'''


[cases.test_evil_invalid_gstate_pointer]
defines.INVALSET = [0x3, 0x1, 0x2]
in = "lfs.c"
code = '''
    // create littlefs
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;

    // create an invalid gstate
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    lfs_fs_prepmove(&lfs, 1, (lfs_block_t [2]){
            (INVALSET & 0x1) ? 0xcccccccc : 0,
            (INVALSET & 0x2) ? 0xcccccccc : 0});
    lfs_dir_commit(&lfs, &mdir, NULL, 0) => 0;
    lfs_deinit(&lfs) => 0;

    // test that mount fails gracefully
    // mount may not fail, but our first alloc should fail when
    // we try to fix the gstate
    lfs_mount(&lfs, cfg) => 0;
    lfs_mkdir(&lfs, "should_fail") => LFS_ERR_CORRUPT;
    lfs_unmount(&lfs) => 0;
'''

# cycle detection/recovery tests

[cases.test_evil_mdir_loop] # metadata-pair threaded-list loop test
in = "lfs.c"
code = '''
    // create littlefs
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;

    // change tail-pointer to point to ourself
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8),
                (lfs_block_t[2]){0, 1}})) => 0;
    lfs_deinit(&lfs) => 0;

    // test that mount fails gracefully
    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
'''

[cases.test_evil_mdir_loop2] # metadata-pair threaded-list 2-length loop test
in = "lfs.c"
code = '''
    // create littlefs with child dir
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;
    lfs_mount(&lfs, cfg) => 0;
    lfs_mkdir(&lfs, "child") => 0;
    lfs_unmount(&lfs) => 0;

    // find child
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_block_t pair[2];
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    lfs_dir_get(&lfs, &mdir,
            LFS_MKTAG(0x7ff, 0x3ff, 0),
            LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair)), pair)
                => LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair));
    lfs_pair_fromle32(pair);
    // change tail-pointer to point to root
    lfs_dir_fetch(&lfs, &mdir, pair) => 0;
    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8),
                (lfs_block_t[2]){0, 1}})) => 0;
    lfs_deinit(&lfs) => 0;

    // test that mount fails gracefully
    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
'''

[cases.test_evil_mdir_loop_child] # metadata-pair threaded-list 1-length child loop test
in = "lfs.c"
code = '''
    // create littlefs with child dir
    lfs_t lfs;
    lfs_format(&lfs, cfg) => 0;
    lfs_mount(&lfs, cfg) => 0;
    lfs_mkdir(&lfs, "child") => 0;
    lfs_unmount(&lfs) => 0;

    // find child
    lfs_init(&lfs, cfg) => 0;
    lfs_mdir_t mdir;
    lfs_block_t pair[2];
    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
    lfs_dir_get(&lfs, &mdir,
            LFS_MKTAG(0x7ff, 0x3ff, 0),
            LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair)), pair)
                => LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair));
    lfs_pair_fromle32(pair);
    // change tail-pointer to point to ourself
    lfs_dir_fetch(&lfs, &mdir, pair) => 0;
    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8), pair})) => 0;
    lfs_deinit(&lfs) => 0;

    // test that mount fails gracefully
    lfs_mount(&lfs, cfg) => LFS_ERR_CORRUPT;
'''