diff options
| -rw-r--r-- | include/linux/bpf_verifier.h | 3 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 69 |
2 files changed, 44 insertions, 28 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 7a7be8c057f2..38b24ee8d8c2 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -521,6 +521,9 @@ bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt); int check_ptr_off_reg(struct bpf_verifier_env *env, const struct bpf_reg_state *reg, int regno); +int check_func_arg_reg_off(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int regno, + enum bpf_arg_type arg_type); int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, u32 regno); int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a57db4b2803c..e37eb6020253 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5359,6 +5359,44 @@ found: return 0; } +int check_func_arg_reg_off(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int regno, + enum bpf_arg_type arg_type) +{ + enum bpf_reg_type type = reg->type; + bool fixed_off_ok = false; + + switch ((u32)type) { + case SCALAR_VALUE: + /* Pointer types where reg offset is explicitly allowed: */ + case PTR_TO_PACKET: + case PTR_TO_PACKET_META: + case PTR_TO_MAP_KEY: + case PTR_TO_MAP_VALUE: + case PTR_TO_MEM: + case PTR_TO_MEM | MEM_RDONLY: + case PTR_TO_MEM | MEM_ALLOC: + case PTR_TO_BUF: + case PTR_TO_BUF | MEM_RDONLY: + case PTR_TO_STACK: + /* Some of the argument types nevertheless require a + * zero register offset. + */ + if (arg_type != ARG_PTR_TO_ALLOC_MEM) + return 0; + break; + /* All the rest must be rejected, except PTR_TO_BTF_ID which allows + * fixed offset. + */ + case PTR_TO_BTF_ID: + fixed_off_ok = true; + break; + default: + break; + } + return __check_ptr_off_reg(env, reg, regno, fixed_off_ok); +} + static int check_func_arg(struct bpf_verifier_env *env, u32 arg, struct bpf_call_arg_meta *meta, const struct bpf_func_proto *fn) @@ -5408,34 +5446,9 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, if (err) return err; - switch ((u32)type) { - case SCALAR_VALUE: - /* Pointer types where reg offset is explicitly allowed: */ - case PTR_TO_PACKET: - case PTR_TO_PACKET_META: - case PTR_TO_MAP_KEY: - case PTR_TO_MAP_VALUE: - case PTR_TO_MEM: - case PTR_TO_MEM | MEM_RDONLY: - case PTR_TO_MEM | MEM_ALLOC: - case PTR_TO_BUF: - case PTR_TO_BUF | MEM_RDONLY: - case PTR_TO_STACK: - /* Some of the argument types nevertheless require a - * zero register offset. - */ - if (arg_type == ARG_PTR_TO_ALLOC_MEM) - goto force_off_check; - break; - /* All the rest must be rejected: */ - default: -force_off_check: - err = __check_ptr_off_reg(env, reg, regno, - type == PTR_TO_BTF_ID); - if (err < 0) - return err; - break; - } + err = check_func_arg_reg_off(env, reg, regno, arg_type); + if (err) + return err; skip_type_check: if (reg->ref_obj_id) { |