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Diffstat (limited to 'include/uapi/linux/landlock.h')
-rw-r--r-- | include/uapi/linux/landlock.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h new file mode 100644 index 000000000..9c4bcc37a --- /dev/null +++ b/include/uapi/linux/landlock.h @@ -0,0 +1,165 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Landlock - User space API + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _UAPI_LINUX_LANDLOCK_H +#define _UAPI_LINUX_LANDLOCK_H + +#include <linux/types.h> + +/** + * struct landlock_ruleset_attr - Ruleset definition + * + * Argument of sys_landlock_create_ruleset(). This structure can grow in + * future versions. + */ +struct landlock_ruleset_attr { + /** + * @handled_access_fs: Bitmask of actions (cf. `Filesystem flags`_) + * that is handled by this ruleset and should then be forbidden if no + * rule explicitly allow them: it is a deny-by-default list that should + * contain as much Landlock access rights as possible. Indeed, all + * Landlock filesystem access rights that are not part of + * handled_access_fs are allowed. This is needed for backward + * compatibility reasons. One exception is the + * %LANDLOCK_ACCESS_FS_REFER access right, which is always implicitly + * handled, but must still be explicitly handled to add new rules with + * this access right. + */ + __u64 handled_access_fs; +}; + +/* + * sys_landlock_create_ruleset() flags: + * + * - %LANDLOCK_CREATE_RULESET_VERSION: Get the highest supported Landlock ABI + * version. + */ +/* clang-format off */ +#define LANDLOCK_CREATE_RULESET_VERSION (1U << 0) +/* clang-format on */ + +/** + * enum landlock_rule_type - Landlock rule type + * + * Argument of sys_landlock_add_rule(). + */ +enum landlock_rule_type { + /** + * @LANDLOCK_RULE_PATH_BENEATH: Type of a &struct + * landlock_path_beneath_attr . + */ + LANDLOCK_RULE_PATH_BENEATH = 1, +}; + +/** + * struct landlock_path_beneath_attr - Path hierarchy definition + * + * Argument of sys_landlock_add_rule(). + */ +struct landlock_path_beneath_attr { + /** + * @allowed_access: Bitmask of allowed actions for this file hierarchy + * (cf. `Filesystem flags`_). + */ + __u64 allowed_access; + /** + * @parent_fd: File descriptor, preferably opened with ``O_PATH``, + * which identifies the parent directory of a file hierarchy, or just a + * file. + */ + __s32 parent_fd; + /* + * This struct is packed to avoid trailing reserved members. + * Cf. security/landlock/syscalls.c:build_check_abi() + */ +} __attribute__((packed)); + +/** + * DOC: fs_access + * + * A set of actions on kernel objects may be defined by an attribute (e.g. + * &struct landlock_path_beneath_attr) including a bitmask of access. + * + * Filesystem flags + * ~~~~~~~~~~~~~~~~ + * + * These flags enable to restrict a sandboxed process to a set of actions on + * files and directories. Files or directories opened before the sandboxing + * are not subject to these restrictions. + * + * A file can only receive these access rights: + * + * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file. + * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access. + * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access. + * + * A directory can receive access rights related to files or directories. The + * following access right is applied to the directory itself, and the + * directories beneath it: + * + * - %LANDLOCK_ACCESS_FS_READ_DIR: Open a directory or list its content. + * + * However, the following access rights only apply to the content of a + * directory, not the directory itself: + * + * - %LANDLOCK_ACCESS_FS_REMOVE_DIR: Remove an empty directory or rename one. + * - %LANDLOCK_ACCESS_FS_REMOVE_FILE: Unlink (or rename) a file. + * - %LANDLOCK_ACCESS_FS_MAKE_CHAR: Create (or rename or link) a character + * device. + * - %LANDLOCK_ACCESS_FS_MAKE_DIR: Create (or rename) a directory. + * - %LANDLOCK_ACCESS_FS_MAKE_REG: Create (or rename or link) a regular file. + * - %LANDLOCK_ACCESS_FS_MAKE_SOCK: Create (or rename or link) a UNIX domain + * socket. + * - %LANDLOCK_ACCESS_FS_MAKE_FIFO: Create (or rename or link) a named pipe. + * - %LANDLOCK_ACCESS_FS_MAKE_BLOCK: Create (or rename or link) a block device. + * - %LANDLOCK_ACCESS_FS_MAKE_SYM: Create (or rename or link) a symbolic link. + * - %LANDLOCK_ACCESS_FS_REFER: Link or rename a file from or to a different + * directory (i.e. reparent a file hierarchy). This access right is + * available since the second version of the Landlock ABI. This is also the + * only access right which is always considered handled by any ruleset in + * such a way that reparenting a file hierarchy is always denied by default. + * To avoid privilege escalation, it is not enough to add a rule with this + * access right. When linking or renaming a file, the destination directory + * hierarchy must also always have the same or a superset of restrictions of + * the source hierarchy. If it is not the case, or if the domain doesn't + * handle this access right, such actions are denied by default with errno + * set to ``EXDEV``. Linking also requires a ``LANDLOCK_ACCESS_FS_MAKE_*`` + * access right on the destination directory, and renaming also requires a + * ``LANDLOCK_ACCESS_FS_REMOVE_*`` access right on the source's (file or + * directory) parent. Otherwise, such actions are denied with errno set to + * ``EACCES``. The ``EACCES`` errno prevails over ``EXDEV`` to let user space + * efficiently deal with an unrecoverable error. + * + * .. warning:: + * + * It is currently not possible to restrict some file-related actions + * accessible through these syscall families: :manpage:`chdir(2)`, + * :manpage:`truncate(2)`, :manpage:`stat(2)`, :manpage:`flock(2)`, + * :manpage:`chmod(2)`, :manpage:`chown(2)`, :manpage:`setxattr(2)`, + * :manpage:`utime(2)`, :manpage:`ioctl(2)`, :manpage:`fcntl(2)`, + * :manpage:`access(2)`. + * Future Landlock evolutions will enable to restrict them. + */ +/* clang-format off */ +#define LANDLOCK_ACCESS_FS_EXECUTE (1ULL << 0) +#define LANDLOCK_ACCESS_FS_WRITE_FILE (1ULL << 1) +#define LANDLOCK_ACCESS_FS_READ_FILE (1ULL << 2) +#define LANDLOCK_ACCESS_FS_READ_DIR (1ULL << 3) +#define LANDLOCK_ACCESS_FS_REMOVE_DIR (1ULL << 4) +#define LANDLOCK_ACCESS_FS_REMOVE_FILE (1ULL << 5) +#define LANDLOCK_ACCESS_FS_MAKE_CHAR (1ULL << 6) +#define LANDLOCK_ACCESS_FS_MAKE_DIR (1ULL << 7) +#define LANDLOCK_ACCESS_FS_MAKE_REG (1ULL << 8) +#define LANDLOCK_ACCESS_FS_MAKE_SOCK (1ULL << 9) +#define LANDLOCK_ACCESS_FS_MAKE_FIFO (1ULL << 10) +#define LANDLOCK_ACCESS_FS_MAKE_BLOCK (1ULL << 11) +#define LANDLOCK_ACCESS_FS_MAKE_SYM (1ULL << 12) +#define LANDLOCK_ACCESS_FS_REFER (1ULL << 13) +/* clang-format on */ + +#endif /* _UAPI_LINUX_LANDLOCK_H */ |