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Merge tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull Landlock LSM from James Morris: "Add Landlock, a new LSM from Mickaël Salaün. Briefly, Landlock provides for unprivileged application sandboxing. From Mickaël's cover letter: "The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem access) for a set of processes. Because Landlock is a stackable LSM [1], it makes possible to create safe security sandboxes as new security layers in addition to the existing system-wide access-controls. This kind of sandbox is expected to help mitigate the security impact of bugs or unexpected/malicious behaviors in user-space applications. Landlock empowers any process, including unprivileged ones, to securely restrict themselves. Landlock is inspired by seccomp-bpf but instead of filtering syscalls and their raw arguments, a Landlock rule can restrict the use of kernel objects like file hierarchies, according to the kernel semantic. Landlock also takes inspiration from other OS sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil. In this current form, Landlock misses some access-control features. This enables to minimize this patch series and ease review. This series still addresses multiple use cases, especially with the combined use of seccomp-bpf: applications with built-in sandboxing, init systems, security sandbox tools and security-oriented APIs [2]" The cover letter and v34 posting is here: https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/ See also: https://landlock.io/ This code has had extensive design discussion and review over several years" Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1] Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2] * tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: landlock: Enable user space to infer supported features landlock: Add user and kernel documentation samples/landlock: Add a sandbox manager example selftests/landlock: Add user space tests landlock: Add syscall implementations arch: Wire up Landlock syscalls fs,security: Add sb_delete hook landlock: Support filesystem access-control LSM: Infrastructure management of the superblock landlock: Add ptrace restrictions landlock: Set up the security framework and manage credentials landlock: Add ruleset and domain management landlock: Add object management

Linus Torvalds committed 5 years ago

Commit 17ae69a2 parents e6f0bf0 3532b0b72 files · +6987 −77Browse files

Showing the changes to include/uapi (2 of 72 files). Show all

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2 files
  1. include/uapi/asm-generic/unistd.h +8 −1
  2. include/uapi/linux/landlock.h +137 −0
include/uapi/asm-generic/unistd.h+8−1
@@ -866,8 +866,15 @@ __SYSCALL(__NR_mount_setattr, sys_mount_setattr) · 865 unmodified lines
866#define __NR_quotactl_path 443866#define __NR_quotactl_path 443
867__SYSCALL(__NR_quotactl_path, sys_quotactl_path)867__SYSCALL(__NR_quotactl_path, sys_quotactl_path)
868 868
869#define __NR_landlock_create_ruleset 444
870__SYSCALL(__NR_landlock_create_ruleset, sys_landlock_create_ruleset)
871#define __NR_landlock_add_rule 445
872__SYSCALL(__NR_landlock_add_rule, sys_landlock_add_rule)
873#define __NR_landlock_restrict_self 446
874__SYSCALL(__NR_landlock_restrict_self, sys_landlock_restrict_self)
875
869#undef __NR_syscalls876#undef __NR_syscalls
870#define __NR_syscalls 444877#define __NR_syscalls 447
871 878
872/*879/*
873 * 32 bit systems traditionally used different880 * 32 bit systems traditionally used different
include/uapi/linux/landlock.h+137−0
@@ -0,0 +1,137 @@
1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * Landlock - User space API
4 *
5 * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
6 * Copyright © 2018-2020 ANSSI
7 */
8
9#ifndef _UAPI_LINUX_LANDLOCK_H
10#define _UAPI_LINUX_LANDLOCK_H
11
12#include <linux/types.h>
13
14/**
15 * struct landlock_ruleset_attr - Ruleset definition
16 *
17 * Argument of sys_landlock_create_ruleset(). This structure can grow in
18 * future versions.
19 */
20struct landlock_ruleset_attr {
21 /**
22 * @handled_access_fs: Bitmask of actions (cf. `Filesystem flags`_)
23 * that is handled by this ruleset and should then be forbidden if no
24 * rule explicitly allow them. This is needed for backward
25 * compatibility reasons.
26 */
27 __u64 handled_access_fs;
28};
29
30/*
31 * sys_landlock_create_ruleset() flags:
32 *
33 * - %LANDLOCK_CREATE_RULESET_VERSION: Get the highest supported Landlock ABI
34 * version.
35 */
36#define LANDLOCK_CREATE_RULESET_VERSION (1U << 0)
37
38/**
39 * enum landlock_rule_type - Landlock rule type
40 *
41 * Argument of sys_landlock_add_rule().
42 */
43enum landlock_rule_type {
44 /**
45 * @LANDLOCK_RULE_PATH_BENEATH: Type of a &struct
46 * landlock_path_beneath_attr .
47 */
48 LANDLOCK_RULE_PATH_BENEATH = 1,
49};
50
51/**
52 * struct landlock_path_beneath_attr - Path hierarchy definition
53 *
54 * Argument of sys_landlock_add_rule().
55 */
56struct landlock_path_beneath_attr {
57 /**
58 * @allowed_access: Bitmask of allowed actions for this file hierarchy
59 * (cf. `Filesystem flags`_).
60 */
61 __u64 allowed_access;
62 /**
63 * @parent_fd: File descriptor, open with ``O_PATH``, which identifies
64 * the parent directory of a file hierarchy, or just a file.
65 */
66 __s32 parent_fd;
67 /*
68 * This struct is packed to avoid trailing reserved members.
69 * Cf. security/landlock/syscalls.c:build_check_abi()
70 */
71} __attribute__((packed));
72
73/**
74 * DOC: fs_access
75 *
76 * A set of actions on kernel objects may be defined by an attribute (e.g.
77 * &struct landlock_path_beneath_attr) including a bitmask of access.
78 *
79 * Filesystem flags
80 * ~~~~~~~~~~~~~~~~
81 *
82 * These flags enable to restrict a sandboxed process to a set of actions on
83 * files and directories. Files or directories opened before the sandboxing
84 * are not subject to these restrictions.
85 *
86 * A file can only receive these access rights:
87 *
88 * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file.
89 * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access.
90 * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access.
91 *
92 * A directory can receive access rights related to files or directories. The
93 * following access right is applied to the directory itself, and the
94 * directories beneath it:
95 *
96 * - %LANDLOCK_ACCESS_FS_READ_DIR: Open a directory or list its content.
97 *
98 * However, the following access rights only apply to the content of a
99 * directory, not the directory itself:
100 *
101 * - %LANDLOCK_ACCESS_FS_REMOVE_DIR: Remove an empty directory or rename one.
102 * - %LANDLOCK_ACCESS_FS_REMOVE_FILE: Unlink (or rename) a file.
103 * - %LANDLOCK_ACCESS_FS_MAKE_CHAR: Create (or rename or link) a character
104 * device.
105 * - %LANDLOCK_ACCESS_FS_MAKE_DIR: Create (or rename) a directory.
106 * - %LANDLOCK_ACCESS_FS_MAKE_REG: Create (or rename or link) a regular file.
107 * - %LANDLOCK_ACCESS_FS_MAKE_SOCK: Create (or rename or link) a UNIX domain
108 * socket.
109 * - %LANDLOCK_ACCESS_FS_MAKE_FIFO: Create (or rename or link) a named pipe.
110 * - %LANDLOCK_ACCESS_FS_MAKE_BLOCK: Create (or rename or link) a block device.
111 * - %LANDLOCK_ACCESS_FS_MAKE_SYM: Create (or rename or link) a symbolic link.
112 *
113 * .. warning::
114 *
115 * It is currently not possible to restrict some file-related actions
116 * accessible through these syscall families: :manpage:`chdir(2)`,
117 * :manpage:`truncate(2)`, :manpage:`stat(2)`, :manpage:`flock(2)`,
118 * :manpage:`chmod(2)`, :manpage:`chown(2)`, :manpage:`setxattr(2)`,
119 * :manpage:`utime(2)`, :manpage:`ioctl(2)`, :manpage:`fcntl(2)`,
120 * :manpage:`access(2)`.
121 * Future Landlock evolutions will enable to restrict them.
122 */
123#define LANDLOCK_ACCESS_FS_EXECUTE (1ULL << 0)
124#define LANDLOCK_ACCESS_FS_WRITE_FILE (1ULL << 1)
125#define LANDLOCK_ACCESS_FS_READ_FILE (1ULL << 2)
126#define LANDLOCK_ACCESS_FS_READ_DIR (1ULL << 3)
127#define LANDLOCK_ACCESS_FS_REMOVE_DIR (1ULL << 4)
128#define LANDLOCK_ACCESS_FS_REMOVE_FILE (1ULL << 5)
129#define LANDLOCK_ACCESS_FS_MAKE_CHAR (1ULL << 6)
130#define LANDLOCK_ACCESS_FS_MAKE_DIR (1ULL << 7)
131#define LANDLOCK_ACCESS_FS_MAKE_REG (1ULL << 8)
132#define LANDLOCK_ACCESS_FS_MAKE_SOCK (1ULL << 9)
133#define LANDLOCK_ACCESS_FS_MAKE_FIFO (1ULL << 10)
134#define LANDLOCK_ACCESS_FS_MAKE_BLOCK (1ULL << 11)
135#define LANDLOCK_ACCESS_FS_MAKE_SYM (1ULL << 12)
136
137#endif /* _UAPI_LINUX_LANDLOCK_H */