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Editing: landlock.h
/* 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 _LINUX_LANDLOCK_H #define _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. * - %LANDLOCK_CREATE_RULESET_ERRATA: Get a bitmask of fixed issues. */ /* clang-format off */ #define LANDLOCK_CREATE_RULESET_VERSION (1U << 0) #define LANDLOCK_CREATE_RULESET_ERRATA (1U << 1) /* 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 /* _LINUX_LANDLOCK_H */
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