static int init_ipmi_si(void)
{
	struct smi_info *e;
	enum ipmi_addr_src type = SI_INVALID;

	if (initialized)
		return 0;

	pr_info("IPMI System Interface driver\n");

	/* If the user gave us a device, they presumably want us to use it */
	if (!ipmi_si_hardcode_find_bmc())
		goto do_scan;

	ipmi_si_platform_init();

	ipmi_si_pci_init();

	ipmi_si_parisc_init();

	/* We prefer devices with interrupts, but in the case of a machine
	   with multiple BMCs we assume that there will be several instances
	   of a given type so if we succeed in registering a type then also
	   try to register everything else of the same type */
do_scan:
	mutex_lock(&smi_infos_lock);
	list_for_each_entry(e, &smi_infos, link) {
		/* Try to register a device if it has an IRQ and we either
		   haven't successfully registered a device yet or this
		   device has the same type as one we successfully registered */
		if (e->io.irq && (!type || e->io.addr_source == type)) {
			if (!try_smi_init(e)) {
				type = e->io.addr_source;
			}
		}
	}

	/* type will only have been set if we successfully registered an si */
	if (type)
		goto skip_fallback_noirq;

	/* Fall back to the preferred device */

	list_for_each_entry(e, &smi_infos, link) {
		if (!e->io.irq && (!type || e->io.addr_source == type)) {
			if (!try_smi_init(e)) {
				type = e->io.addr_source;
			}
		}
	}

skip_fallback_noirq:
	initialized = 1;
	mutex_unlock(&smi_infos_lock);

	if (type)
		return 0;

	mutex_lock(&smi_infos_lock);
	if (unload_when_empty && list_empty(&smi_infos)) {
		mutex_unlock(&smi_infos_lock);
		cleanup_ipmi_si();
		pr_warn("Unable to find any System Interface(s)\n");
		return -ENODEV;
	} else {
		mutex_unlock(&smi_infos_lock);
		return 0;
	}
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.