Commit 831deb29 authored by Anton Protopopov's avatar Anton Protopopov Committed by Alexei Starovoitov
Browse files

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: default avatarAnton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/r/20230719092952.41202-2-aspsk@isovalent.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 8daf8477

kernel/bpf/verifier.c

+12 −9
Original line number Diff line number Diff line
@@ -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 */