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Diffstat (limited to 'kernel/bpf/bpf_lsm.c')
-rw-r--r--kernel/bpf/bpf_lsm.c258
1 files changed, 237 insertions, 21 deletions
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index 1622a44d1617..967492b65185 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -11,11 +11,11 @@
#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>
+#include <linux/bpf-cgroup.h>
/* For every LSM hook that allows attachment of BPF programs, declare a nop
* function where a BPF program can be attached.
@@ -35,18 +35,103 @@ BTF_SET_START(bpf_lsm_hooks)
#undef LSM_HOOK
BTF_SET_END(bpf_lsm_hooks)
+BTF_SET_START(bpf_lsm_disabled_hooks)
+BTF_ID(func, bpf_lsm_vm_enough_memory)
+BTF_ID(func, bpf_lsm_inode_need_killpriv)
+BTF_ID(func, bpf_lsm_inode_getsecurity)
+BTF_ID(func, bpf_lsm_inode_listsecurity)
+BTF_ID(func, bpf_lsm_inode_copy_up_xattr)
+BTF_ID(func, bpf_lsm_getselfattr)
+BTF_ID(func, bpf_lsm_getprocattr)
+BTF_ID(func, bpf_lsm_setprocattr)
+#ifdef CONFIG_KEYS
+BTF_ID(func, bpf_lsm_key_getsecurity)
+#endif
+#ifdef CONFIG_AUDIT
+BTF_ID(func, bpf_lsm_audit_rule_match)
+#endif
+BTF_ID(func, bpf_lsm_ismaclabel)
+BTF_SET_END(bpf_lsm_disabled_hooks)
+
+/* List of LSM hooks that should operate on 'current' cgroup regardless
+ * of function signature.
+ */
+BTF_SET_START(bpf_lsm_current_hooks)
+/* operate on freshly allocated sk without any cgroup association */
+#ifdef CONFIG_SECURITY_NETWORK
+BTF_ID(func, bpf_lsm_sk_alloc_security)
+BTF_ID(func, bpf_lsm_sk_free_security)
+#endif
+BTF_SET_END(bpf_lsm_current_hooks)
+
+/* List of LSM hooks that trigger while the socket is properly locked.
+ */
+BTF_SET_START(bpf_lsm_locked_sockopt_hooks)
+#ifdef CONFIG_SECURITY_NETWORK
+BTF_ID(func, bpf_lsm_sock_graft)
+BTF_ID(func, bpf_lsm_inet_csk_clone)
+BTF_ID(func, bpf_lsm_inet_conn_established)
+#endif
+BTF_SET_END(bpf_lsm_locked_sockopt_hooks)
+
+/* List of LSM hooks that trigger while the socket is _not_ locked,
+ * but it's ok to call bpf_{g,s}etsockopt because the socket is still
+ * in the early init phase.
+ */
+BTF_SET_START(bpf_lsm_unlocked_sockopt_hooks)
+#ifdef CONFIG_SECURITY_NETWORK
+BTF_ID(func, bpf_lsm_socket_post_create)
+BTF_ID(func, bpf_lsm_socket_socketpair)
+#endif
+BTF_SET_END(bpf_lsm_unlocked_sockopt_hooks)
+
+#ifdef CONFIG_CGROUP_BPF
+void bpf_lsm_find_cgroup_shim(const struct bpf_prog *prog,
+ bpf_func_t *bpf_func)
+{
+ const struct btf_param *args __maybe_unused;
+
+ if (btf_type_vlen(prog->aux->attach_func_proto) < 1 ||
+ btf_id_set_contains(&bpf_lsm_current_hooks,
+ prog->aux->attach_btf_id)) {
+ *bpf_func = __cgroup_bpf_run_lsm_current;
+ return;
+ }
+
+#ifdef CONFIG_NET
+ args = btf_params(prog->aux->attach_func_proto);
+
+ if (args[0].type == btf_sock_ids[BTF_SOCK_TYPE_SOCKET])
+ *bpf_func = __cgroup_bpf_run_lsm_socket;
+ else if (args[0].type == btf_sock_ids[BTF_SOCK_TYPE_SOCK])
+ *bpf_func = __cgroup_bpf_run_lsm_sock;
+ else
+#endif
+ *bpf_func = __cgroup_bpf_run_lsm_current;
+}
+#endif
+
int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog,
const struct bpf_prog *prog)
{
+ u32 btf_id = prog->aux->attach_btf_id;
+ const char *func_name = prog->aux->attach_func_name;
+
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)) {
+ if (btf_id_set_contains(&bpf_lsm_disabled_hooks, btf_id)) {
+ bpf_log(vlog, "attach_btf_id %u points to disabled hook %s\n",
+ btf_id, func_name);
+ return -EINVAL;
+ }
+
+ if (!btf_id_set_contains(&bpf_lsm_hooks, 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);
+ btf_id, func_name);
return -EINVAL;
}
@@ -67,7 +152,7 @@ BPF_CALL_2(bpf_bprm_opts_set, struct linux_binprm *, bprm, u64, flags)
BTF_ID_LIST_SINGLE(bpf_bprm_opts_set_btf_ids, struct, linux_binprm)
-const static struct bpf_func_proto bpf_bprm_opts_set_proto = {
+static const struct bpf_func_proto bpf_bprm_opts_set_proto = {
.func = bpf_bprm_opts_set,
.gpl_only = false,
.ret_type = RET_INTEGER,
@@ -88,9 +173,10 @@ static bool bpf_ima_inode_hash_allowed(const struct bpf_prog *prog)
BTF_ID_LIST_SINGLE(bpf_ima_inode_hash_btf_ids, struct, inode)
-const static struct bpf_func_proto bpf_ima_inode_hash_proto = {
+static const struct bpf_func_proto bpf_ima_inode_hash_proto = {
.func = bpf_ima_inode_hash,
.gpl_only = false,
+ .might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_ima_inode_hash_btf_ids[0],
@@ -99,44 +185,116 @@ const static struct bpf_func_proto bpf_ima_inode_hash_proto = {
.allowed = bpf_ima_inode_hash_allowed,
};
+BPF_CALL_3(bpf_ima_file_hash, struct file *, file, void *, dst, u32, size)
+{
+ return ima_file_hash(file, dst, size);
+}
+
+BTF_ID_LIST_SINGLE(bpf_ima_file_hash_btf_ids, struct, file)
+
+static const struct bpf_func_proto bpf_ima_file_hash_proto = {
+ .func = bpf_ima_file_hash,
+ .gpl_only = false,
+ .might_sleep = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_BTF_ID,
+ .arg1_btf_id = &bpf_ima_file_hash_btf_ids[0],
+ .arg2_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .allowed = bpf_ima_inode_hash_allowed,
+};
+
+BPF_CALL_1(bpf_get_attach_cookie, void *, ctx)
+{
+ struct bpf_trace_run_ctx *run_ctx;
+
+ run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
+ return run_ctx->bpf_cookie;
+}
+
+static const struct bpf_func_proto bpf_get_attach_cookie_proto = {
+ .func = bpf_get_attach_cookie,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+};
+
static const struct bpf_func_proto *
bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
+ const struct bpf_func_proto *func_proto;
+
+ if (prog->expected_attach_type == BPF_LSM_CGROUP) {
+ func_proto = cgroup_common_func_proto(func_id, prog);
+ if (func_proto)
+ return func_proto;
+ }
+
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;
+#ifdef CONFIG_NET
case BPF_FUNC_sk_storage_get:
return &bpf_sk_storage_get_proto;
case BPF_FUNC_sk_storage_delete:
return &bpf_sk_storage_delete_proto;
+#endif /* CONFIG_NET */
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;
+ return &bpf_ima_inode_hash_proto;
+ case BPF_FUNC_ima_file_hash:
+ return &bpf_ima_file_hash_proto;
+ case BPF_FUNC_get_attach_cookie:
+ return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto : NULL;
+#ifdef CONFIG_NET
+ case BPF_FUNC_setsockopt:
+ if (prog->expected_attach_type != BPF_LSM_CGROUP)
+ return NULL;
+ if (btf_id_set_contains(&bpf_lsm_locked_sockopt_hooks,
+ prog->aux->attach_btf_id))
+ return &bpf_sk_setsockopt_proto;
+ if (btf_id_set_contains(&bpf_lsm_unlocked_sockopt_hooks,
+ prog->aux->attach_btf_id))
+ return &bpf_unlocked_sk_setsockopt_proto;
+ return NULL;
+ case BPF_FUNC_getsockopt:
+ if (prog->expected_attach_type != BPF_LSM_CGROUP)
+ return NULL;
+ if (btf_id_set_contains(&bpf_lsm_locked_sockopt_hooks,
+ prog->aux->attach_btf_id))
+ return &bpf_sk_getsockopt_proto;
+ if (btf_id_set_contains(&bpf_lsm_unlocked_sockopt_hooks,
+ prog->aux->attach_btf_id))
+ return &bpf_unlocked_sk_getsockopt_proto;
+ return NULL;
+#endif
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.
+ * to "sleep" and thus can be used for sleepable 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_map_create)
+BTF_ID(func, bpf_lsm_bpf_map_free)
BTF_ID(func, bpf_lsm_bpf_prog)
+BTF_ID(func, bpf_lsm_bpf_prog_load)
+BTF_ID(func, bpf_lsm_bpf_prog_free)
+BTF_ID(func, bpf_lsm_bpf_token_create)
+BTF_ID(func, bpf_lsm_bpf_token_free)
+BTF_ID(func, bpf_lsm_bpf_token_cmd)
+BTF_ID(func, bpf_lsm_bpf_token_capable)
BTF_ID(func, bpf_lsm_bprm_check_security)
BTF_ID(func, bpf_lsm_bprm_committed_creds)
BTF_ID(func, bpf_lsm_bprm_committing_creds)
@@ -148,12 +306,9 @@ 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_post_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)
@@ -169,11 +324,20 @@ 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_kernel_read_file)
BTF_ID(func, bpf_lsm_kernfs_init_security)
-#ifdef CONFIG_KEYS
-BTF_ID(func, bpf_lsm_key_free)
-#endif /* CONFIG_KEYS */
+#ifdef CONFIG_SECURITY_PATH
+BTF_ID(func, bpf_lsm_path_unlink)
+BTF_ID(func, bpf_lsm_path_mkdir)
+BTF_ID(func, bpf_lsm_path_rmdir)
+BTF_ID(func, bpf_lsm_path_truncate)
+BTF_ID(func, bpf_lsm_path_symlink)
+BTF_ID(func, bpf_lsm_path_link)
+BTF_ID(func, bpf_lsm_path_rename)
+BTF_ID(func, bpf_lsm_path_chmod)
+BTF_ID(func, bpf_lsm_path_chown)
+#endif /* CONFIG_SECURITY_PATH */
BTF_ID(func, bpf_lsm_mmap_file)
BTF_ID(func, bpf_lsm_netlink_send)
@@ -191,6 +355,8 @@ BTF_ID(func, bpf_lsm_sb_umount)
BTF_ID(func, bpf_lsm_settime)
#ifdef CONFIG_SECURITY_NETWORK
+BTF_ID(func, bpf_lsm_inet_conn_established)
+
BTF_ID(func, bpf_lsm_socket_accept)
BTF_ID(func, bpf_lsm_socket_bind)
BTF_ID(func, bpf_lsm_socket_connect)
@@ -209,17 +375,34 @@ BTF_ID(func, bpf_lsm_socket_socketpair)
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_ID(func, bpf_lsm_userns_create)
BTF_SET_END(sleepable_lsm_hooks)
+BTF_SET_START(untrusted_lsm_hooks)
+BTF_ID(func, bpf_lsm_bpf_map_free)
+BTF_ID(func, bpf_lsm_bpf_prog_free)
+BTF_ID(func, bpf_lsm_file_alloc_security)
+BTF_ID(func, bpf_lsm_file_free_security)
+#ifdef CONFIG_SECURITY_NETWORK
+BTF_ID(func, bpf_lsm_sk_alloc_security)
+BTF_ID(func, bpf_lsm_sk_free_security)
+#endif /* CONFIG_SECURITY_NETWORK */
+BTF_ID(func, bpf_lsm_task_free)
+BTF_SET_END(untrusted_lsm_hooks)
+
bool bpf_lsm_is_sleepable_hook(u32 btf_id)
{
return btf_id_set_contains(&sleepable_lsm_hooks, btf_id);
}
+bool bpf_lsm_is_trusted(const struct bpf_prog *prog)
+{
+ return !btf_id_set_contains(&untrusted_lsm_hooks, prog->aux->attach_btf_id);
+}
+
const struct bpf_prog_ops lsm_prog_ops = {
};
@@ -227,3 +410,36 @@ const struct bpf_verifier_ops lsm_verifier_ops = {
.get_func_proto = bpf_lsm_func_proto,
.is_valid_access = btf_ctx_access,
};
+
+/* hooks return 0 or 1 */
+BTF_SET_START(bool_lsm_hooks)
+#ifdef CONFIG_SECURITY_NETWORK_XFRM
+BTF_ID(func, bpf_lsm_xfrm_state_pol_flow_match)
+#endif
+#ifdef CONFIG_AUDIT
+BTF_ID(func, bpf_lsm_audit_rule_known)
+#endif
+BTF_ID(func, bpf_lsm_inode_xattr_skipcap)
+BTF_SET_END(bool_lsm_hooks)
+
+int bpf_lsm_get_retval_range(const struct bpf_prog *prog,
+ struct bpf_retval_range *retval_range)
+{
+ /* no return value range for void hooks */
+ if (!prog->aux->attach_func_proto->type)
+ return -EINVAL;
+
+ if (btf_id_set_contains(&bool_lsm_hooks, prog->aux->attach_btf_id)) {
+ retval_range->minval = 0;
+ retval_range->maxval = 1;
+ } else {
+ /* All other available LSM hooks, except task_prctl, return 0
+ * on success and negative error code on failure.
+ * To keep things simple, we only allow bpf progs to return 0
+ * or negative errno for task_prctl too.
+ */
+ retval_range->minval = -MAX_ERRNO;
+ retval_range->maxval = 0;
+ }
+ return 0;
+}