2 files changed, 209 insertions, 26 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 51e8b4bee0c8..596471189176 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -5615,21 +5615,46 @@ static u8 bpf_ctx_convert_map[] = {
 #undef BPF_MAP_TYPE
 #undef BPF_LINK_TYPE
 
-const struct btf_member *
-btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
-		      const struct btf_type *t, enum bpf_prog_type prog_type,
-		      int arg)
+static const struct btf_type *find_canonical_prog_ctx_type(enum bpf_prog_type prog_type)
 {
 	const struct btf_type *conv_struct;
-	const struct btf_type *ctx_struct;
 	const struct btf_member *ctx_type;
-	const char *tname, *ctx_tname;
 
 	conv_struct = bpf_ctx_convert.t;
-	if (!conv_struct) {
-		bpf_log(log, "btf_vmlinux is malformed\n");
+	if (!conv_struct)
 		return NULL;
-	}
+	/* prog_type is valid bpf program type. No need for bounds check. */
+	ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
+	/* ctx_type is a pointer to prog_ctx_type in vmlinux.
+	 * Like 'struct __sk_buff'
+	 */
+	return btf_type_by_id(btf_vmlinux, ctx_type->type);
+}
+
+static int find_kern_ctx_type_id(enum bpf_prog_type prog_type)
+{
+	const struct btf_type *conv_struct;
+	const struct btf_member *ctx_type;
+
+	conv_struct = bpf_ctx_convert.t;
+	if (!conv_struct)
+		return -EFAULT;
+	/* prog_type is valid bpf program type. No need for bounds check. */
+	ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1;
+	/* ctx_type is a pointer to prog_ctx_type in vmlinux.
+	 * Like 'struct sk_buff'
+	 */
+	return ctx_type->type;
+}
+
+const struct btf_type *
+btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
+		      const struct btf_type *t, enum bpf_prog_type prog_type,
+		      int arg)
+{
+	const struct btf_type *ctx_type;
+	const char *tname, *ctx_tname;
+
 	t = btf_type_by_id(btf, t->type);
 	while (btf_type_is_modifier(t))
 		t = btf_type_by_id(btf, t->type);
@@ -5646,17 +5671,15 @@ btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
 		bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
 		return NULL;
 	}
-	/* prog_type is valid bpf program type. No need for bounds check. */
-	ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
-	/* ctx_struct is a pointer to prog_ctx_type in vmlinux.
-	 * Like 'struct __sk_buff'
-	 */
-	ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
-	if (!ctx_struct)
+
+	ctx_type = find_canonical_prog_ctx_type(prog_type);
+	if (!ctx_type) {
+		bpf_log(log, "btf_vmlinux is malformed\n");
 		/* should not happen */
 		return NULL;
+	}
 again:
-	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
+	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off);
 	if (!ctx_tname) {
 		/* should not happen */
 		bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
@@ -5677,28 +5700,167 @@ again:
 		/* bpf_user_pt_regs_t is a typedef, so resolve it to
 		 * underlying struct and check name again
 		 */
-		if (!btf_type_is_modifier(ctx_struct))
+		if (!btf_type_is_modifier(ctx_type))
 			return NULL;
-		while (btf_type_is_modifier(ctx_struct))
-			ctx_struct = btf_type_by_id(btf_vmlinux, ctx_struct->type);
+		while (btf_type_is_modifier(ctx_type))
+			ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type);
 		goto again;
 	}
 	return ctx_type;
 }
 
+/* forward declarations for arch-specific underlying types of
+ * bpf_user_pt_regs_t; this avoids the need for arch-specific #ifdef
+ * compilation guards below for BPF_PROG_TYPE_PERF_EVENT checks, but still
+ * works correctly with __builtin_types_compatible_p() on respective
+ * architectures
+ */
+struct user_regs_struct;
+struct user_pt_regs;
+
+static int btf_validate_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
+				      const struct btf_type *t, int arg,
+				      enum bpf_prog_type prog_type,
+				      enum bpf_attach_type attach_type)
+{
+	const struct btf_type *ctx_type;
+	const char *tname, *ctx_tname;
+
+	if (!btf_is_ptr(t)) {
+		bpf_log(log, "arg#%d type isn't a pointer\n", arg);
+		return -EINVAL;
+	}
+	t = btf_type_by_id(btf, t->type);
+
+	/* KPROBE and PERF_EVENT programs allow bpf_user_pt_regs_t typedef */
+	if (prog_type == BPF_PROG_TYPE_KPROBE || prog_type == BPF_PROG_TYPE_PERF_EVENT) {
+		while (btf_type_is_modifier(t) && !btf_type_is_typedef(t))
+			t = btf_type_by_id(btf, t->type);
+
+		if (btf_type_is_typedef(t)) {
+			tname = btf_name_by_offset(btf, t->name_off);
+			if (tname && strcmp(tname, "bpf_user_pt_regs_t") == 0)
+				return 0;
+		}
+	}
+
+	/* all other program types don't use typedefs for context type */
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+
+	/* `void *ctx __arg_ctx` is always valid */
+	if (btf_type_is_void(t))
+		return 0;
+
+	tname = btf_name_by_offset(btf, t->name_off);
+	if (str_is_empty(tname)) {
+		bpf_log(log, "arg#%d type doesn't have a name\n", arg);
+		return -EINVAL;
+	}
+
+	/* special cases */
+	switch (prog_type) {
+	case BPF_PROG_TYPE_KPROBE:
+		if (__btf_type_is_struct(t) && strcmp(tname, "pt_regs") == 0)
+			return 0;
+		break;
+	case BPF_PROG_TYPE_PERF_EVENT:
+		if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct pt_regs) &&
+		    __btf_type_is_struct(t) && strcmp(tname, "pt_regs") == 0)
+			return 0;
+		if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_pt_regs) &&
+		    __btf_type_is_struct(t) && strcmp(tname, "user_pt_regs") == 0)
+			return 0;
+		if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_regs_struct) &&
+		    __btf_type_is_struct(t) && strcmp(tname, "user_regs_struct") == 0)
+			return 0;
+		break;
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
+		/* allow u64* as ctx */
+		if (btf_is_int(t) && t->size == 8)
+			return 0;
+		break;
+	case BPF_PROG_TYPE_TRACING:
+		switch (attach_type) {
+		case BPF_TRACE_RAW_TP:
+			/* tp_btf program is TRACING, so need special case here */
+			if (__btf_type_is_struct(t) &&
+			    strcmp(tname, "bpf_raw_tracepoint_args") == 0)
+				return 0;
+			/* allow u64* as ctx */
+			if (btf_is_int(t) && t->size == 8)
+				return 0;
+			break;
+		case BPF_TRACE_ITER:
+			/* allow struct bpf_iter__xxx types only */
+			if (__btf_type_is_struct(t) &&
+			    strncmp(tname, "bpf_iter__", sizeof("bpf_iter__") - 1) == 0)
+				return 0;
+			break;
+		case BPF_TRACE_FENTRY:
+		case BPF_TRACE_FEXIT:
+		case BPF_MODIFY_RETURN:
+			/* allow u64* as ctx */
+			if (btf_is_int(t) && t->size == 8)
+				return 0;
+			break;
+		default:
+			break;
+		}
+		break;
+	case BPF_PROG_TYPE_LSM:
+	case BPF_PROG_TYPE_STRUCT_OPS:
+		/* allow u64* as ctx */
+		if (btf_is_int(t) && t->size == 8)
+			return 0;
+		break;
+	case BPF_PROG_TYPE_TRACEPOINT:
+	case BPF_PROG_TYPE_SYSCALL:
+	case BPF_PROG_TYPE_EXT:
+		return 0; /* anything goes */
+	default:
+		break;
+	}
+
+	ctx_type = find_canonical_prog_ctx_type(prog_type);
+	if (!ctx_type) {
+		/* should not happen */
+		bpf_log(log, "btf_vmlinux is malformed\n");
+		return -EINVAL;
+	}
+
+	/* resolve typedefs and check that underlying structs are matching as well */
+	while (btf_type_is_modifier(ctx_type))
+		ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type);
+
+	/* if program type doesn't have distinctly named struct type for
+	 * context, then __arg_ctx argument can only be `void *`, which we
+	 * already checked above
+	 */
+	if (!__btf_type_is_struct(ctx_type)) {
+		bpf_log(log, "arg#%d should be void pointer\n", arg);
+		return -EINVAL;
+	}
+
+	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off);
+	if (!__btf_type_is_struct(t) || strcmp(ctx_tname, tname) != 0) {
+		bpf_log(log, "arg#%d should be `struct %s *`\n", arg, ctx_tname);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
 				     struct btf *btf,
 				     const struct btf_type *t,
 				     enum bpf_prog_type prog_type,
 				     int arg)
 {
-	const struct btf_member *prog_ctx_type, *kern_ctx_type;
-
-	prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
-	if (!prog_ctx_type)
+	if (!btf_get_prog_ctx_type(log, btf, t, prog_type, arg))
 		return -ENOENT;
-	kern_ctx_type = prog_ctx_type + 1;
-	return kern_ctx_type->type;
+	return find_kern_ctx_type_id(prog_type);
 }
 
 int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type)
@@ -6934,6 +7096,23 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
 		return -EINVAL;
 	}
 
+	for (i = 0; i < nargs; i++) {
+		const char *tag;
+
+		if (sub->args[i].arg_type != ARG_PTR_TO_CTX)
+			continue;
+
+		/* check if arg has "arg:ctx" tag */
+		t = btf_type_by_id(btf, args[i].type);
+		tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:");
+		if (IS_ERR_OR_NULL(tag) || strcmp(tag, "ctx") != 0)
+			continue;
+
+		if (btf_validate_prog_ctx_type(log, btf, t, i, prog_type,
+					       prog->expected_attach_type))
+			return -EINVAL;
+	}
+
 	sub->arg_cnt = nargs;
 	sub->args_cached = true;
 
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index adbf330d364b..65f598694d55 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -12826,6 +12826,10 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	}
 
 	switch (base_type(ptr_reg->type)) {
+	case PTR_TO_FLOW_KEYS:
+		if (known)
+			break;
+		fallthrough;
 	case CONST_PTR_TO_MAP:
 		/* smin_val represents the known value */
 		if (known && smin_val == 0 && opcode == BPF_ADD)