1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Google LLC.
*/
#include <linux/filter.h>
#include <linux/bpf.h>
#include <linux/btf.h>
#include <linux/binfmts.h>
#include <linux/lsm_hooks.h>
#include <linux/bpf_lsm.h>
#include <linux/kallsyms.h>
#include <linux/bpf_verifier.h>
#include <net/bpf_sk_storage.h>
#include <linux/bpf_local_storage.h>
#include <linux/btf_ids.h>
#include <linux/ima.h>
/* For every LSM hook that allows attachment of BPF programs, declare a nop
* function where a BPF program can be attached.
*/
#define LSM_HOOK(RET, DEFAULT, NAME, ...) \
noinline RET bpf_lsm_##NAME(__VA_ARGS__) \
{ \
return DEFAULT; \
}
#include <linux/lsm_hook_defs.h>
#undef LSM_HOOK
#define LSM_HOOK(RET, DEFAULT, NAME, ...) BTF_ID(func, bpf_lsm_##NAME)
BTF_SET_START(bpf_lsm_hooks)
#include <linux/lsm_hook_defs.h>
#undef LSM_HOOK
BTF_SET_END(bpf_lsm_hooks)
int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog,
const struct bpf_prog *prog)
{
if (!prog->gpl_compatible) {
bpf_log(vlog,
"LSM programs must have a GPL compatible license\n");
return -EINVAL;
}
if (!btf_id_set_contains(&bpf_lsm_hooks, prog->aux->attach_btf_id)) {
bpf_log(vlog, "attach_btf_id %u points to wrong type name %s\n",
prog->aux->attach_btf_id, prog->aux->attach_func_name);
return -EINVAL;
}
return 0;
}
/* Mask for all the currently supported BPRM option flags */
#define BPF_F_BRPM_OPTS_MASK BPF_F_BPRM_SECUREEXEC
BPF_CALL_2(bpf_bprm_opts_set, struct linux_binprm *, bprm, u64, flags)
{
if (flags & ~BPF_F_BRPM_OPTS_MASK)
return -EINVAL;
bprm->secureexec = (flags & BPF_F_BPRM_SECUREEXEC);
return 0;
}
BTF_ID_LIST_SINGLE(bpf_bprm_opts_set_btf_ids, struct, linux_binprm)
const static struct bpf_func_proto bpf_bprm_opts_set_proto = {
.func = bpf_bprm_opts_set,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_bprm_opts_set_btf_ids[0],
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_ima_inode_hash, struct inode *, inode, void *, dst, u32, size)
{
return ima_inode_hash(inode, dst, size);
}
static bool bpf_ima_inode_hash_allowed(const struct bpf_prog *prog)
{
return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
}
BTF_ID_LIST_SINGLE(bpf_ima_inode_hash_btf_ids, struct, inode)
const static struct bpf_func_proto bpf_ima_inode_hash_proto = {
.func = bpf_ima_inode_hash,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_ima_inode_hash_btf_ids[0],
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
.arg3_type = ARG_CONST_SIZE,
.allowed = bpf_ima_inode_hash_allowed,
};
static const struct bpf_func_proto *
bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_inode_storage_get:
return &bpf_inode_storage_get_proto;
case BPF_FUNC_inode_storage_delete:
return &bpf_inode_storage_delete_proto;
case BPF_FUNC_sk_storage_get:
return &bpf_sk_storage_get_proto;
case BPF_FUNC_sk_storage_delete:
return &bpf_sk_storage_delete_proto;
case BPF_FUNC_spin_lock:
return &bpf_spin_lock_proto;
case BPF_FUNC_spin_unlock:
return &bpf_spin_unlock_proto;
case BPF_FUNC_task_storage_get:
return &bpf_task_storage_get_proto;
case BPF_FUNC_task_storage_delete:
return &bpf_task_storage_delete_proto;
case BPF_FUNC_bprm_opts_set:
return &bpf_bprm_opts_set_proto;
case BPF_FUNC_ima_inode_hash:
return prog->aux->sleepable ? &bpf_ima_inode_hash_proto : NULL;
default:
return tracing_prog_func_proto(func_id, prog);
}
}
/* The set of hooks which are called without pagefaults disabled and are allowed
* to "sleep" and thus can be used for sleeable BPF programs.
*/
BTF_SET_START(sleepable_lsm_hooks)
BTF_ID(func, bpf_lsm_bpf)
BTF_ID(func, bpf_lsm_bpf_map)
BTF_ID(func, bpf_lsm_bpf_map_alloc_security)
BTF_ID(func, bpf_lsm_bpf_map_free_security)
BTF_ID(func, bpf_lsm_bpf_prog)
BTF_ID(func, bpf_lsm_bprm_check_security)
BTF_ID(func, bpf_lsm_bprm_committed_creds)
BTF_ID(func, bpf_lsm_bprm_committing_creds)
BTF_ID(func, bpf_lsm_bprm_creds_for_exec)
BTF_ID(func, bpf_lsm_bprm_creds_from_file)
BTF_ID(func, bpf_lsm_capget)
BTF_ID(func, bpf_lsm_capset)
BTF_ID(func, bpf_lsm_cred_prepare)
BTF_ID(func, bpf_lsm_file_ioctl)
BTF_ID(func, bpf_lsm_file_lock)
BTF_ID(func, bpf_lsm_file_open)
BTF_ID(func, bpf_lsm_file_receive)
#ifdef CONFIG_SECURITY_NETWORK
BTF_ID(func, bpf_lsm_inet_conn_established)
#endif /* CONFIG_SECURITY_NETWORK */
BTF_ID(func, bpf_lsm_inode_create)
BTF_ID(func, bpf_lsm_inode_free_security)
BTF_ID(func, bpf_lsm_inode_getattr)
BTF_ID(func, bpf_lsm_inode_getxattr)
BTF_ID(func, bpf_lsm_inode_mknod)
BTF_ID(func, bpf_lsm_inode_need_killpriv)
BTF_ID(func, bpf_lsm_inode_post_setxattr)
BTF_ID(func, bpf_lsm_inode_readlink)
BTF_ID(func, bpf_lsm_inode_rename)
BTF_ID(func, bpf_lsm_inode_rmdir)
BTF_ID(func, bpf_lsm_inode_setattr)
BTF_ID(func, bpf_lsm_inode_setxattr)
BTF_ID(func, bpf_lsm_inode_symlink)
BTF_ID(func, bpf_lsm_inode_unlink)
BTF_ID(func, bpf_lsm_kernel_module_request)
BTF_ID(func, bpf_lsm_kernfs_init_security)
#ifdef CONFIG_KEYS
BTF_ID(func, bpf_lsm_key_free)
#endif /* CONFIG_KEYS */
BTF_ID(func, bpf_lsm_mmap_file)
BTF_ID(func, bpf_lsm_netlink_send)
BTF_ID(func, bpf_lsm_path_notify)
BTF_ID(func, bpf_lsm_release_secctx)
BTF_ID(func, bpf_lsm_sb_alloc_security)
BTF_ID(func, bpf_lsm_sb_eat_lsm_opts)
BTF_ID(func, bpf_lsm_sb_kern_mount)
BTF_ID(func, bpf_lsm_sb_mount)
BTF_ID(func, bpf_lsm_sb_remount)
BTF_ID(func, bpf_lsm_sb_set_mnt_opts)
BTF_ID(func, bpf_lsm_sb_show_options)
BTF_ID(func, bpf_lsm_sb_statfs)
BTF_ID(func, bpf_lsm_sb_umount)
BTF_ID(func, bpf_lsm_settime)
#ifdef CONFIG_SECURITY_NETWORK
BTF_ID(func, bpf_lsm_socket_accept)
BTF_ID(func, bpf_lsm_socket_bind)
BTF_ID(func, bpf_lsm_socket_connect)
BTF_ID(func, bpf_lsm_socket_create)
BTF_ID(func, bpf_lsm_socket_getpeername)
BTF_ID(func, bpf_lsm_socket_getpeersec_dgram)
BTF_ID(func, bpf_lsm_socket_getsockname)
BTF_ID(func, bpf_lsm_socket_getsockopt)
BTF_ID(func, bpf_lsm_socket_listen)
BTF_ID(func, bpf_lsm_socket_post_create)
BTF_ID(func, bpf_lsm_socket_recvmsg)
BTF_ID(func, bpf_lsm_socket_sendmsg)
BTF_ID(func, bpf_lsm_socket_shutdown)
BTF_ID(func, bpf_lsm_socket_socketpair)
#endif /* CONFIG_SECURITY_NETWORK */
BTF_ID(func, bpf_lsm_syslog)
BTF_ID(func, bpf_lsm_task_alloc)
BTF_ID(func, bpf_lsm_task_getsecid)
BTF_ID(func, bpf_lsm_task_prctl)
BTF_ID(func, bpf_lsm_task_setscheduler)
BTF_ID(func, bpf_lsm_task_to_inode)
BTF_SET_END(sleepable_lsm_hooks)
bool bpf_lsm_is_sleepable_hook(u32 btf_id)
{
return btf_id_set_contains(&sleepable_lsm_hooks, btf_id);
}
const struct bpf_prog_ops lsm_prog_ops = {
};
const struct bpf_verifier_ops lsm_verifier_ops = {
.get_func_proto = bpf_lsm_func_proto,
.is_valid_access = btf_ctx_access,
};
|
