diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 5061ccd8b2dc..c107392b0ba7 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -390,7 +390,10 @@ enum bpf_type_flag { */ PTR_UNTRUSTED = BIT(6 + BPF_BASE_TYPE_BITS), - __BPF_TYPE_LAST_FLAG = PTR_UNTRUSTED, + MEM_UNINIT = BIT(7 + BPF_BASE_TYPE_BITS), + + __BPF_TYPE_FLAG_MAX, + __BPF_TYPE_LAST_FLAG = __BPF_TYPE_FLAG_MAX - 1, }; /* Max number of base types. */ @@ -409,16 +412,11 @@ enum bpf_arg_type { ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */ ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */ ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */ - ARG_PTR_TO_UNINIT_MAP_VALUE, /* pointer to valid memory used to store a map value */ - /* the following constraints used to prototype bpf_memcmp() and other - * functions that access data on eBPF program stack + /* Used to prototype bpf_memcmp() and other functions that access data + * on eBPF program stack */ ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value) */ - ARG_PTR_TO_UNINIT_MEM, /* pointer to memory does not need to be initialized, - * helper function must fill all bytes or clear - * them in error case. - */ ARG_CONST_SIZE, /* number of bytes accessed from memory */ ARG_CONST_SIZE_OR_ZERO, /* number of bytes accessed from memory or 0 */ @@ -450,6 +448,10 @@ enum bpf_arg_type { ARG_PTR_TO_ALLOC_MEM_OR_NULL = PTR_MAYBE_NULL | ARG_PTR_TO_ALLOC_MEM, ARG_PTR_TO_STACK_OR_NULL = PTR_MAYBE_NULL | ARG_PTR_TO_STACK, ARG_PTR_TO_BTF_ID_OR_NULL = PTR_MAYBE_NULL | ARG_PTR_TO_BTF_ID, + /* pointer to memory does not need to be initialized, helper function must fill + * all bytes or clear them in error case. + */ + ARG_PTR_TO_UNINIT_MEM = MEM_UNINIT | ARG_PTR_TO_MEM, /* This must be the last entry. Its purpose is to ensure the enum is * wide enough to hold the higher bits reserved for bpf_type_flag. diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index d5f104a39092..bad96131a510 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -103,7 +103,7 @@ const struct bpf_func_proto bpf_map_pop_elem_proto = { .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_CONST_MAP_PTR, - .arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE, + .arg2_type = ARG_PTR_TO_MAP_VALUE | MEM_UNINIT, }; BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value) @@ -116,7 +116,7 @@ const struct bpf_func_proto bpf_map_peek_elem_proto = { .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_CONST_MAP_PTR, - .arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE, + .arg2_type = ARG_PTR_TO_MAP_VALUE | MEM_UNINIT, }; BPF_CALL_3(bpf_map_lookup_percpu_elem, struct bpf_map *, map, void *, key, u32, cpu) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 05c1b6656824..9b59581026f8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5377,12 +5377,6 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno, return 0; } -static bool arg_type_is_mem_ptr(enum bpf_arg_type type) -{ - return base_type(type) == ARG_PTR_TO_MEM || - base_type(type) == ARG_PTR_TO_UNINIT_MEM; -} - static bool arg_type_is_mem_size(enum bpf_arg_type type) { return type == ARG_CONST_SIZE || @@ -5522,7 +5516,6 @@ static const struct bpf_reg_types kptr_types = { .types = { PTR_TO_MAP_VALUE } } static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_MAP_KEY] = &map_key_value_types, [ARG_PTR_TO_MAP_VALUE] = &map_key_value_types, - [ARG_PTR_TO_UNINIT_MAP_VALUE] = &map_key_value_types, [ARG_CONST_SIZE] = &scalar_types, [ARG_CONST_SIZE_OR_ZERO] = &scalar_types, [ARG_CONST_ALLOC_SIZE_OR_ZERO] = &scalar_types, @@ -5536,7 +5529,6 @@ static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_BTF_ID] = &btf_ptr_types, [ARG_PTR_TO_SPIN_LOCK] = &spin_lock_types, [ARG_PTR_TO_MEM] = &mem_types, - [ARG_PTR_TO_UNINIT_MEM] = &mem_types, [ARG_PTR_TO_ALLOC_MEM] = &alloc_mem_types, [ARG_PTR_TO_INT] = &int_ptr_types, [ARG_PTR_TO_LONG] = &int_ptr_types, @@ -5710,8 +5702,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, return -EACCES; } - if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE || - base_type(arg_type) == ARG_PTR_TO_UNINIT_MAP_VALUE) { + if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE) { err = resolve_map_arg_type(env, meta, &arg_type); if (err) return err; @@ -5797,8 +5788,7 @@ skip_type_check: err = check_helper_mem_access(env, regno, meta->map_ptr->key_size, false, NULL); - } else if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE || - base_type(arg_type) == ARG_PTR_TO_UNINIT_MAP_VALUE) { + } else if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE) { if (type_may_be_null(arg_type) && register_is_null(reg)) return 0; @@ -5810,7 +5800,7 @@ skip_type_check: verbose(env, "invalid map_ptr to access map->value\n"); return -EACCES; } - meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE); + meta->raw_mode = arg_type & MEM_UNINIT; err = check_helper_mem_access(env, regno, meta->map_ptr->value_size, false, meta); @@ -5837,11 +5827,11 @@ skip_type_check: return -EACCES; } else if (arg_type == ARG_PTR_TO_FUNC) { meta->subprogno = reg->subprogno; - } else if (arg_type_is_mem_ptr(arg_type)) { + } else if (base_type(arg_type) == ARG_PTR_TO_MEM) { /* The access to this pointer is only checked when we hit the * next is_mem_size argument below. */ - meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MEM); + meta->raw_mode = arg_type & MEM_UNINIT; } else if (arg_type_is_mem_size(arg_type)) { bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO); @@ -6194,10 +6184,8 @@ static bool check_raw_mode_ok(const struct bpf_func_proto *fn) static bool check_args_pair_invalid(enum bpf_arg_type arg_curr, enum bpf_arg_type arg_next) { - return (arg_type_is_mem_ptr(arg_curr) && - !arg_type_is_mem_size(arg_next)) || - (!arg_type_is_mem_ptr(arg_curr) && - arg_type_is_mem_size(arg_next)); + return (base_type(arg_curr) == ARG_PTR_TO_MEM) != + arg_type_is_mem_size(arg_next); } static bool check_arg_pair_ok(const struct bpf_func_proto *fn) @@ -6208,7 +6196,7 @@ static bool check_arg_pair_ok(const struct bpf_func_proto *fn) * helper function specification. */ if (arg_type_is_mem_size(fn->arg1_type) || - arg_type_is_mem_ptr(fn->arg5_type) || + base_type(fn->arg5_type) == ARG_PTR_TO_MEM || check_args_pair_invalid(fn->arg1_type, fn->arg2_type) || check_args_pair_invalid(fn->arg2_type, fn->arg3_type) || check_args_pair_invalid(fn->arg3_type, fn->arg4_type) ||