1 // SPDX-License-Identifier: GPL-2.0 2 3 /* 4 * Copyright (C) 2020 Google LLC. 5 */ 6 7 #include <linux/filter.h> 8 #include <linux/bpf.h> 9 #include <linux/btf.h> 10 #include <linux/lsm_hooks.h> 11 #include <linux/bpf_lsm.h> 12 #include <linux/kallsyms.h> 13 #include <linux/bpf_verifier.h> 14 #include <net/bpf_sk_storage.h> 15 #include <linux/bpf_local_storage.h> 16 #include <linux/btf_ids.h> 17 18 /* For every LSM hook that allows attachment of BPF programs, declare a nop 19 * function where a BPF program can be attached. 20 */ 21 #define LSM_HOOK(RET, DEFAULT, NAME, ...) \ 22 noinline RET bpf_lsm_##NAME(__VA_ARGS__) \ 23 { \ 24 return DEFAULT; \ 25 } 26 27 #include <linux/lsm_hook_defs.h> 28 #undef LSM_HOOK 29 30 #define LSM_HOOK(RET, DEFAULT, NAME, ...) BTF_ID(func, bpf_lsm_##NAME) 31 BTF_SET_START(bpf_lsm_hooks) 32 #include <linux/lsm_hook_defs.h> 33 #undef LSM_HOOK 34 BTF_SET_END(bpf_lsm_hooks) 35 36 int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog, 37 const struct bpf_prog *prog) 38 { 39 if (!prog->gpl_compatible) { 40 bpf_log(vlog, 41 "LSM programs must have a GPL compatible license\n"); 42 return -EINVAL; 43 } 44 45 if (!btf_id_set_contains(&bpf_lsm_hooks, prog->aux->attach_btf_id)) { 46 bpf_log(vlog, "attach_btf_id %u points to wrong type name %s\n", 47 prog->aux->attach_btf_id, prog->aux->attach_func_name); 48 return -EINVAL; 49 } 50 51 return 0; 52 } 53 54 static const struct bpf_func_proto * 55 bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 56 { 57 switch (func_id) { 58 case BPF_FUNC_inode_storage_get: 59 return &bpf_inode_storage_get_proto; 60 case BPF_FUNC_inode_storage_delete: 61 return &bpf_inode_storage_delete_proto; 62 case BPF_FUNC_sk_storage_get: 63 return &bpf_sk_storage_get_proto; 64 case BPF_FUNC_sk_storage_delete: 65 return &bpf_sk_storage_delete_proto; 66 case BPF_FUNC_spin_lock: 67 return &bpf_spin_lock_proto; 68 case BPF_FUNC_spin_unlock: 69 return &bpf_spin_unlock_proto; 70 case BPF_FUNC_task_storage_get: 71 return &bpf_task_storage_get_proto; 72 case BPF_FUNC_task_storage_delete: 73 return &bpf_task_storage_delete_proto; 74 default: 75 return tracing_prog_func_proto(func_id, prog); 76 } 77 } 78 79 /* The set of hooks which are called without pagefaults disabled and are allowed 80 * to "sleep" and thus can be used for sleeable BPF programs. 81 */ 82 BTF_SET_START(sleepable_lsm_hooks) 83 BTF_ID(func, bpf_lsm_bpf) 84 BTF_ID(func, bpf_lsm_bpf_map) 85 BTF_ID(func, bpf_lsm_bpf_map_alloc_security) 86 BTF_ID(func, bpf_lsm_bpf_map_free_security) 87 BTF_ID(func, bpf_lsm_bpf_prog) 88 BTF_ID(func, bpf_lsm_bprm_check_security) 89 BTF_ID(func, bpf_lsm_bprm_committed_creds) 90 BTF_ID(func, bpf_lsm_bprm_committing_creds) 91 BTF_ID(func, bpf_lsm_bprm_creds_for_exec) 92 BTF_ID(func, bpf_lsm_bprm_creds_from_file) 93 BTF_ID(func, bpf_lsm_capget) 94 BTF_ID(func, bpf_lsm_capset) 95 BTF_ID(func, bpf_lsm_cred_prepare) 96 BTF_ID(func, bpf_lsm_file_ioctl) 97 BTF_ID(func, bpf_lsm_file_lock) 98 BTF_ID(func, bpf_lsm_file_open) 99 BTF_ID(func, bpf_lsm_file_receive) 100 BTF_ID(func, bpf_lsm_inet_conn_established) 101 BTF_ID(func, bpf_lsm_inode_create) 102 BTF_ID(func, bpf_lsm_inode_free_security) 103 BTF_ID(func, bpf_lsm_inode_getattr) 104 BTF_ID(func, bpf_lsm_inode_getxattr) 105 BTF_ID(func, bpf_lsm_inode_mknod) 106 BTF_ID(func, bpf_lsm_inode_need_killpriv) 107 BTF_ID(func, bpf_lsm_inode_post_setxattr) 108 BTF_ID(func, bpf_lsm_inode_readlink) 109 BTF_ID(func, bpf_lsm_inode_rename) 110 BTF_ID(func, bpf_lsm_inode_rmdir) 111 BTF_ID(func, bpf_lsm_inode_setattr) 112 BTF_ID(func, bpf_lsm_inode_setxattr) 113 BTF_ID(func, bpf_lsm_inode_symlink) 114 BTF_ID(func, bpf_lsm_inode_unlink) 115 BTF_ID(func, bpf_lsm_kernel_module_request) 116 BTF_ID(func, bpf_lsm_kernfs_init_security) 117 BTF_ID(func, bpf_lsm_key_free) 118 BTF_ID(func, bpf_lsm_mmap_file) 119 BTF_ID(func, bpf_lsm_netlink_send) 120 BTF_ID(func, bpf_lsm_path_notify) 121 BTF_ID(func, bpf_lsm_release_secctx) 122 BTF_ID(func, bpf_lsm_sb_alloc_security) 123 BTF_ID(func, bpf_lsm_sb_eat_lsm_opts) 124 BTF_ID(func, bpf_lsm_sb_kern_mount) 125 BTF_ID(func, bpf_lsm_sb_mount) 126 BTF_ID(func, bpf_lsm_sb_remount) 127 BTF_ID(func, bpf_lsm_sb_set_mnt_opts) 128 BTF_ID(func, bpf_lsm_sb_show_options) 129 BTF_ID(func, bpf_lsm_sb_statfs) 130 BTF_ID(func, bpf_lsm_sb_umount) 131 BTF_ID(func, bpf_lsm_settime) 132 BTF_ID(func, bpf_lsm_socket_accept) 133 BTF_ID(func, bpf_lsm_socket_bind) 134 BTF_ID(func, bpf_lsm_socket_connect) 135 BTF_ID(func, bpf_lsm_socket_create) 136 BTF_ID(func, bpf_lsm_socket_getpeername) 137 BTF_ID(func, bpf_lsm_socket_getpeersec_dgram) 138 BTF_ID(func, bpf_lsm_socket_getsockname) 139 BTF_ID(func, bpf_lsm_socket_getsockopt) 140 BTF_ID(func, bpf_lsm_socket_listen) 141 BTF_ID(func, bpf_lsm_socket_post_create) 142 BTF_ID(func, bpf_lsm_socket_recvmsg) 143 BTF_ID(func, bpf_lsm_socket_sendmsg) 144 BTF_ID(func, bpf_lsm_socket_shutdown) 145 BTF_ID(func, bpf_lsm_socket_socketpair) 146 BTF_ID(func, bpf_lsm_syslog) 147 BTF_ID(func, bpf_lsm_task_alloc) 148 BTF_ID(func, bpf_lsm_task_getsecid) 149 BTF_ID(func, bpf_lsm_task_prctl) 150 BTF_ID(func, bpf_lsm_task_setscheduler) 151 BTF_ID(func, bpf_lsm_task_to_inode) 152 BTF_SET_END(sleepable_lsm_hooks) 153 154 bool bpf_lsm_is_sleepable_hook(u32 btf_id) 155 { 156 return btf_id_set_contains(&sleepable_lsm_hooks, btf_id); 157 } 158 159 const struct bpf_prog_ops lsm_prog_ops = { 160 }; 161 162 const struct bpf_verifier_ops lsm_verifier_ops = { 163 .get_func_proto = bpf_lsm_func_proto, 164 .is_valid_access = btf_ctx_access, 165 }; 166