static void print_verifier_state(struct bpf_verifier_env *env,
				 const struct bpf_func_state *state)
{
	const struct bpf_reg_state *reg;
	enum bpf_reg_type t;
	int i;

	if (state->frameno)
		verbose(env, " frame%d:", state->frameno);
	for (i = 0; i < MAX_BPF_REG; i++) {
		reg = &state->regs[i];
		t = reg->type;
		if (t == NOT_INIT)
			continue;
		verbose(env, " R%d", i);
		print_liveness(env, reg->live);
		verbose(env, "=%s", reg_type_str[t]);
		if ((t == SCALAR_VALUE || t == PTR_TO_STACK) &&
		    tnum_is_const(reg->var_off)) {
			/* reg->off should be 0 for SCALAR_VALUE */
			verbose(env, "%lld", reg->var_off.value + reg->off);
			if (t == PTR_TO_STACK)
				verbose(env, ",call_%d", func(env, reg)->callsite);
		} else {
			verbose(env, "(id=%d", reg->id);
			if (t != SCALAR_VALUE)
				verbose(env, ",off=%d", reg->off);
			if (type_is_pkt_pointer(t))
				verbose(env, ",r=%d", reg->range);
			else if (t == CONST_PTR_TO_MAP ||
				 t == PTR_TO_MAP_VALUE ||
				 t == PTR_TO_MAP_VALUE_OR_NULL)
				verbose(env, ",ks=%d,vs=%d",
					reg->map_ptr->key_size,
					reg->map_ptr->value_size);
			if (tnum_is_const(reg->var_off)) {
				/* Typically an immediate SCALAR_VALUE, but
				 * could be a pointer whose offset is too big
				 * for reg->off
				 */
				verbose(env, ",imm=%llx", reg->var_off.value);
			} else {
				if (reg->smin_value != reg->umin_value &&
				    reg->smin_value != S64_MIN)
					verbose(env, ",smin_value=%lld",
						(long long)reg->smin_value);
				if (reg->smax_value != reg->umax_value &&
				    reg->smax_value != S64_MAX)
					verbose(env, ",smax_value=%lld",
						(long long)reg->smax_value);
				if (reg->umin_value != 0)
					verbose(env, ",umin_value=%llu",
						(unsigned long long)reg->umin_value);
				if (reg->umax_value != U64_MAX)
					verbose(env, ",umax_value=%llu",
						(unsigned long long)reg->umax_value);
				if (!tnum_is_unknown(reg->var_off)) {
					char tn_buf[48];

					tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
					verbose(env, ",var_off=%s", tn_buf);
				}
			}
			verbose(env, ")");
		}
	}
	for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
		if (state->stack[i].slot_type[0] == STACK_SPILL) {
			verbose(env, " fp%d",
				(-i - 1) * BPF_REG_SIZE);
			print_liveness(env, state->stack[i].spilled_ptr.live);
			verbose(env, "=%s",
				reg_type_str[state->stack[i].spilled_ptr.type]);
		}
		if (state->stack[i].slot_type[0] == STACK_ZERO)
			verbose(env, " fp%d=0", (-i - 1) * BPF_REG_SIZE);
	}
	verbose(env, "\n");
}

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