static bool check_reg_sane_offset(struct bpf_verifier_env *env,
				  const struct bpf_reg_state *reg,
				  enum bpf_reg_type type)
{
	bool known = tnum_is_const(reg->var_off);
	s64 val = reg->var_off.value;
	s64 smin = reg->smin_value;

	if (known && (val >= BPF_MAX_VAR_OFF || val <= -BPF_MAX_VAR_OFF)) {
		verbose(env, "math between %s pointer and %lld is not allowed\n",
			reg_type_str[type], val);
		return false;
	}

	if (reg->off >= BPF_MAX_VAR_OFF || reg->off <= -BPF_MAX_VAR_OFF) {
		verbose(env, "%s pointer offset %d is not allowed\n",
			reg_type_str[type], reg->off);
		return false;
	}

	if (smin == S64_MIN) {
		verbose(env, "math between %s pointer and register with unbounded min value is not allowed\n",
			reg_type_str[type]);
		return false;
	}

	if (smin >= BPF_MAX_VAR_OFF || smin <= -BPF_MAX_VAR_OFF) {
		verbose(env, "value %lld makes %s pointer be out of bounds\n",
			smin, reg_type_str[type]);
		return false;
	}

	return true;
}

The product reads data past the end, or before the beginning, of the intended buffer.