From 831deb2976de4458adae4daee56aa6f740ed4acc Mon Sep 17 00:00:00 2001 From: Anton Protopopov Date: Wed, 19 Jul 2023 09:29:49 +0000 Subject: [PATCH] bpf: consider types listed in reg2btf_ids as trusted The reg2btf_ids array contains a list of types for which we can (and need) to find a corresponding static BTF id. All the types in the list can be considered as trusted for purposes of kfuncs. Signed-off-by: Anton Protopopov Link: https://lore.kernel.org/r/20230719092952.41202-2-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 0b9da95331d7..05123feab378 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5413,12 +5413,24 @@ static bool is_flow_key_reg(struct bpf_verifier_env *env, int regno) return reg->type == PTR_TO_FLOW_KEYS; } +static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { +#ifdef CONFIG_NET + [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], + [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], + [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP], +#endif +}; + static bool is_trusted_reg(const struct bpf_reg_state *reg) { /* A referenced register is always trusted. */ if (reg->ref_obj_id) return true; + /* Types listed in the reg2btf_ids are always trusted */ + if (reg2btf_ids[base_type(reg->type)]) + return true; + /* If a register is not referenced, it is trusted if it has the * MEM_ALLOC or PTR_TRUSTED type modifiers, and no others. Some of the * other type modifiers may be safe, but we elect to take an opt-in @@ -10052,15 +10064,6 @@ static bool __btf_type_is_scalar_struct(struct bpf_verifier_env *env, return true; } - -static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { -#ifdef CONFIG_NET - [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], - [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], - [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP], -#endif -}; - enum kfunc_ptr_arg_type { KF_ARG_PTR_TO_CTX, KF_ARG_PTR_TO_ALLOC_BTF_ID, /* Allocated object */ -- 2.20.1