Revert BPF token-related functionality

This patch includes the following revert (one  conflicting BPF FS
patch and three token patch sets, represented by merge commits):
  - revert 0f5d5454c723 "Merge branch 'bpf-fs-mount-options-parsing-follow-ups'";
  - revert 750e785796bb "bpf: Support uid and gid when mounting bpffs";
  - revert 733763285acf "Merge branch 'bpf-token-support-in-libbpf-s-bpf-object'";
  - revert c35919dcce28 "Merge branch 'bpf-token-and-bpf-fs-based-delegation'".

Link: https://lore.kernel.org/bpf/CAHk-=wg7JuFYwGy=GOMbRCtOL+jwSQsdUaBsRWkDVYbxipbM5A@mail.gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

1 files changed, 56 insertions, 159 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 8faa1a20edf8..1bf9805ee185 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1011,8 +1011,8 @@ int map_check_no_btf(const struct bpf_map *map,
 	return -ENOTSUPP;
 }
 
-static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
-			 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
+static int map_check_btf(struct bpf_map *map, const struct btf *btf,
+			 u32 btf_key_id, u32 btf_value_id)
 {
 	const struct btf_type *key_type, *value_type;
 	u32 key_size, value_size;
@@ -1040,7 +1040,7 @@ static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
 	if (!IS_ERR_OR_NULL(map->record)) {
 		int i;
 
-		if (!bpf_token_capable(token, CAP_BPF)) {
+		if (!bpf_capable()) {
 			ret = -EPERM;
 			goto free_map_tab;
 		}
@@ -1123,17 +1123,11 @@ free_map_tab:
 	return ret;
 }
 
-static bool bpf_net_capable(void)
-{
-	return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
-}
-
-#define BPF_MAP_CREATE_LAST_FIELD map_token_fd
+#define BPF_MAP_CREATE_LAST_FIELD map_extra
 /* called via syscall */
 static int map_create(union bpf_attr *attr)
 {
 	const struct bpf_map_ops *ops;
-	struct bpf_token *token = NULL;
 	int numa_node = bpf_map_attr_numa_node(attr);
 	u32 map_type = attr->map_type;
 	struct bpf_map *map;
@@ -1184,32 +1178,14 @@ static int map_create(union bpf_attr *attr)
 	if (!ops->map_mem_usage)
 		return -EINVAL;
 
-	if (attr->map_token_fd) {
-		token = bpf_token_get_from_fd(attr->map_token_fd);
-		if (IS_ERR(token))
-			return PTR_ERR(token);
-
-		/* if current token doesn't grant map creation permissions,
-		 * then we can't use this token, so ignore it and rely on
-		 * system-wide capabilities checks
-		 */
-		if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
-		    !bpf_token_allow_map_type(token, attr->map_type)) {
-			bpf_token_put(token);
-			token = NULL;
-		}
-	}
-
-	err = -EPERM;
-
 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
 	 * creation for unprivileged users; other actions depend
 	 * on fd availability and access to bpffs, so are dependent on
 	 * object creation success. Even with unprivileged BPF disabled,
 	 * capability checks are still carried out.
 	 */
-	if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
-		goto put_token;
+	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
+		return -EPERM;
 
 	/* check privileged map type permissions */
 	switch (map_type) {
@@ -1242,27 +1218,25 @@ static int map_create(union bpf_attr *attr)
 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
 	case BPF_MAP_TYPE_STRUCT_OPS:
 	case BPF_MAP_TYPE_CPUMAP:
-		if (!bpf_token_capable(token, CAP_BPF))
-			goto put_token;
+		if (!bpf_capable())
+			return -EPERM;
 		break;
 	case BPF_MAP_TYPE_SOCKMAP:
 	case BPF_MAP_TYPE_SOCKHASH:
 	case BPF_MAP_TYPE_DEVMAP:
 	case BPF_MAP_TYPE_DEVMAP_HASH:
 	case BPF_MAP_TYPE_XSKMAP:
-		if (!bpf_token_capable(token, CAP_NET_ADMIN))
-			goto put_token;
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
 		break;
 	default:
 		WARN(1, "unsupported map type %d", map_type);
-		goto put_token;
+		return -EPERM;
 	}
 
 	map = ops->map_alloc(attr);
-	if (IS_ERR(map)) {
-		err = PTR_ERR(map);
-		goto put_token;
-	}
+	if (IS_ERR(map))
+		return PTR_ERR(map);
 	map->ops = ops;
 	map->map_type = map_type;
 
@@ -1299,7 +1273,7 @@ static int map_create(union bpf_attr *attr)
 		map->btf = btf;
 
 		if (attr->btf_value_type_id) {
-			err = map_check_btf(map, token, btf, attr->btf_key_type_id,
+			err = map_check_btf(map, btf, attr->btf_key_type_id,
 					    attr->btf_value_type_id);
 			if (err)
 				goto free_map;
@@ -1311,16 +1285,15 @@ static int map_create(union bpf_attr *attr)
 			attr->btf_vmlinux_value_type_id;
 	}
 
-	err = security_bpf_map_create(map, attr, token);
+	err = security_bpf_map_alloc(map);
 	if (err)
-		goto free_map_sec;
+		goto free_map;
 
 	err = bpf_map_alloc_id(map);
 	if (err)
 		goto free_map_sec;
 
 	bpf_map_save_memcg(map);
-	bpf_token_put(token);
 
 	err = bpf_map_new_fd(map, f_flags);
 	if (err < 0) {
@@ -1341,8 +1314,6 @@ free_map_sec:
 free_map:
 	btf_put(map->btf);
 	map->ops->map_free(map);
-put_token:
-	bpf_token_put(token);
 	return err;
 }
 
@@ -2173,7 +2144,7 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu)
 	kvfree(aux->func_info);
 	kfree(aux->func_info_aux);
 	free_uid(aux->user);
-	security_bpf_prog_free(aux->prog);
+	security_bpf_prog_free(aux);
 	bpf_prog_free(aux->prog);
 }
 
@@ -2619,15 +2590,13 @@ static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
 }
 
 /* last field in 'union bpf_attr' used by this command */
-#define BPF_PROG_LOAD_LAST_FIELD prog_token_fd
+#define	BPF_PROG_LOAD_LAST_FIELD log_true_size
 
 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 {
 	enum bpf_prog_type type = attr->prog_type;
 	struct bpf_prog *prog, *dst_prog = NULL;
 	struct btf *attach_btf = NULL;
-	struct bpf_token *token = NULL;
-	bool bpf_cap;
 	int err;
 	char license[128];
 
@@ -2644,31 +2613,10 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 				 BPF_F_TEST_REG_INVARIANTS))
 		return -EINVAL;
 
-	bpf_prog_load_fixup_attach_type(attr);
-
-	if (attr->prog_token_fd) {
-		token = bpf_token_get_from_fd(attr->prog_token_fd);
-		if (IS_ERR(token))
-			return PTR_ERR(token);
-		/* if current token doesn't grant prog loading permissions,
-		 * then we can't use this token, so ignore it and rely on
-		 * system-wide capabilities checks
-		 */
-		if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
-		    !bpf_token_allow_prog_type(token, attr->prog_type,
-					       attr->expected_attach_type)) {
-			bpf_token_put(token);
-			token = NULL;
-		}
-	}
-
-	bpf_cap = bpf_token_capable(token, CAP_BPF);
-	err = -EPERM;
-
 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
-	    !bpf_cap)
-		goto put_token;
+	    !bpf_capable())
+		return -EPERM;
 
 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
 	 * creation for unprivileged users; other actions depend
@@ -2677,23 +2625,21 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 	 * capability checks are still carried out for these
 	 * and other operations.
 	 */
-	if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
-		goto put_token;
+	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
+		return -EPERM;
 
 	if (attr->insn_cnt == 0 ||
-	    attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
-		err = -E2BIG;
-		goto put_token;
-	}
+	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
+		return -E2BIG;
 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
-	    !bpf_cap)
-		goto put_token;
+	    !bpf_capable())
+		return -EPERM;
 
-	if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
-		goto put_token;
-	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
-		goto put_token;
+	if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (is_perfmon_prog_type(type) && !perfmon_capable())
+		return -EPERM;
 
 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
 	 * or btf, we need to check which one it is
@@ -2703,33 +2649,27 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 		if (IS_ERR(dst_prog)) {
 			dst_prog = NULL;
 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
-			if (IS_ERR(attach_btf)) {
-				err = -EINVAL;
-				goto put_token;
-			}
+			if (IS_ERR(attach_btf))
+				return -EINVAL;
 			if (!btf_is_kernel(attach_btf)) {
 				/* attaching through specifying bpf_prog's BTF
 				 * objects directly might be supported eventually
 				 */
 				btf_put(attach_btf);
-				err = -ENOTSUPP;
-				goto put_token;
+				return -ENOTSUPP;
 			}
 		}
 	} else if (attr->attach_btf_id) {
 		/* fall back to vmlinux BTF, if BTF type ID is specified */
 		attach_btf = bpf_get_btf_vmlinux();
-		if (IS_ERR(attach_btf)) {
-			err = PTR_ERR(attach_btf);
-			goto put_token;
-		}
-		if (!attach_btf) {
-			err = -EINVAL;
-			goto put_token;
-		}
+		if (IS_ERR(attach_btf))
+			return PTR_ERR(attach_btf);
+		if (!attach_btf)
+			return -EINVAL;
 		btf_get(attach_btf);
 	}
 
+	bpf_prog_load_fixup_attach_type(attr);
 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
 				       attach_btf, attr->attach_btf_id,
 				       dst_prog)) {
@@ -2737,8 +2677,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 			bpf_prog_put(dst_prog);
 		if (attach_btf)
 			btf_put(attach_btf);
-		err = -EINVAL;
-		goto put_token;
+		return -EINVAL;
 	}
 
 	/* plain bpf_prog allocation */
@@ -2748,8 +2687,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 			bpf_prog_put(dst_prog);
 		if (attach_btf)
 			btf_put(attach_btf);
-		err = -EINVAL;
-		goto put_token;
+		return -ENOMEM;
 	}
 
 	prog->expected_attach_type = attr->expected_attach_type;
@@ -2760,9 +2698,9 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
 
-	/* move token into prog->aux, reuse taken refcnt */
-	prog->aux->token = token;
-	token = NULL;
+	err = security_bpf_prog_alloc(prog->aux);
+	if (err)
+		goto free_prog;
 
 	prog->aux->user = get_current_user();
 	prog->len = attr->insn_cnt;
@@ -2771,12 +2709,12 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 	if (copy_from_bpfptr(prog->insns,
 			     make_bpfptr(attr->insns, uattr.is_kernel),
 			     bpf_prog_insn_size(prog)) != 0)
-		goto free_prog;
+		goto free_prog_sec;
 	/* copy eBPF program license from user space */
 	if (strncpy_from_bpfptr(license,
 				make_bpfptr(attr->license, uattr.is_kernel),
 				sizeof(license) - 1) < 0)
-		goto free_prog;
+		goto free_prog_sec;
 	license[sizeof(license) - 1] = 0;
 
 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
@@ -2790,29 +2728,25 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 	if (bpf_prog_is_dev_bound(prog->aux)) {
 		err = bpf_prog_dev_bound_init(prog, attr);
 		if (err)
-			goto free_prog;
+			goto free_prog_sec;
 	}
 
 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
 		if (err)
-			goto free_prog;
+			goto free_prog_sec;
 	}
 
 	/* find program type: socket_filter vs tracing_filter */
 	err = find_prog_type(type, prog);
 	if (err < 0)
-		goto free_prog;
+		goto free_prog_sec;
 
 	prog->aux->load_time = ktime_get_boottime_ns();
 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
 			       sizeof(attr->prog_name));
 	if (err < 0)
-		goto free_prog;
-
-	err = security_bpf_prog_load(prog, attr, token);
-	if (err)
 		goto free_prog_sec;
 
 	/* run eBPF verifier */
@@ -2858,16 +2792,13 @@ free_used_maps:
 	 */
 	__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
 	return err;
-
 free_prog_sec:
-	security_bpf_prog_free(prog);
-free_prog:
 	free_uid(prog->aux->user);
+	security_bpf_prog_free(prog->aux);
+free_prog:
 	if (prog->aux->attach_btf)
 		btf_put(prog->aux->attach_btf);
 	bpf_prog_free(prog);
-put_token:
-	bpf_token_put(token);
 	return err;
 }
 
@@ -3857,7 +3788,7 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
 	case BPF_PROG_TYPE_SK_LOOKUP:
 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
 	case BPF_PROG_TYPE_CGROUP_SKB:
-		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
+		if (!capable(CAP_NET_ADMIN))
 			/* cg-skb progs can be loaded by unpriv user.
 			 * check permissions at attach time.
 			 */
@@ -4060,7 +3991,7 @@ static int bpf_prog_detach(const union bpf_attr *attr)
 static int bpf_prog_query(const union bpf_attr *attr,
 			  union bpf_attr __user *uattr)
 {
-	if (!bpf_net_capable())
+	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 	if (CHECK_ATTR(BPF_PROG_QUERY))
 		return -EINVAL;
@@ -4828,31 +4759,15 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
 	return err;
 }
 
-#define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
+#define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size
 
 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
 {
-	struct bpf_token *token = NULL;
-
 	if (CHECK_ATTR(BPF_BTF_LOAD))
 		return -EINVAL;
 
-	if (attr->btf_token_fd) {
-		token = bpf_token_get_from_fd(attr->btf_token_fd);
-		if (IS_ERR(token))
-			return PTR_ERR(token);
-		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
-			bpf_token_put(token);
-			token = NULL;
-		}
-	}
-
-	if (!bpf_token_capable(token, CAP_BPF)) {
-		bpf_token_put(token);
+	if (!bpf_capable())
 		return -EPERM;
-	}
-
-	bpf_token_put(token);
 
 	return btf_new_fd(attr, uattr, uattr_size);
 }
@@ -5470,20 +5385,6 @@ out_prog_put:
 	return ret;
 }
 
-#define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
-
-static int token_create(union bpf_attr *attr)
-{
-	if (CHECK_ATTR(BPF_TOKEN_CREATE))
-		return -EINVAL;
-
-	/* no flags are supported yet */
-	if (attr->token_create.flags)
-		return -EINVAL;
-
-	return bpf_token_create(attr);
-}
-
 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
 {
 	union bpf_attr attr;
@@ -5617,9 +5518,6 @@ static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
 	case BPF_PROG_BIND_MAP:
 		err = bpf_prog_bind_map(&attr);
 		break;
-	case BPF_TOKEN_CREATE:
-		err = token_create(&attr);
-		break;
 	default:
 		err = -EINVAL;
 		break;
@@ -5726,7 +5624,7 @@ static const struct bpf_func_proto bpf_sys_bpf_proto = {
 const struct bpf_func_proto * __weak
 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
-	return bpf_base_func_proto(func_id, prog);
+	return bpf_base_func_proto(func_id);
 }
 
 BPF_CALL_1(bpf_sys_close, u32, fd)
@@ -5776,8 +5674,7 @@ syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
 	switch (func_id) {
 	case BPF_FUNC_sys_bpf:
-		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
-		       ? NULL : &bpf_sys_bpf_proto;
+		return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto;
 	case BPF_FUNC_btf_find_by_name_kind:
 		return &bpf_btf_find_by_name_kind_proto;
 	case BPF_FUNC_sys_close: