static int smi_start_processing(void            *send_info,
				struct ipmi_smi *intf)
{
	struct smi_info *new_smi = send_info;
	int             enable = 0;

	new_smi->intf = intf;

	/* Set up the timer that drives the interface. */
	timer_setup(&new_smi->si_timer, smi_timeout, 0);
	new_smi->timer_can_start = true;
	smi_mod_timer(new_smi, jiffies + SI_TIMEOUT_JIFFIES);

	/* Try to claim any interrupts. */
	if (new_smi->io.irq_setup) {
		new_smi->io.irq_handler_data = new_smi;
		new_smi->io.irq_setup(&new_smi->io);
	}

	/*
	 * Check if the user forcefully enabled the daemon.
	 */
	if (new_smi->si_num < num_force_kipmid)
		enable = force_kipmid[new_smi->si_num];
	/*
	 * The BT interface is efficient enough to not need a thread,
	 * and there is no need for a thread if we have interrupts.
	 */
	else if ((new_smi->io.si_type != SI_BT) && (!new_smi->io.irq))
		enable = 1;

	if (enable) {
		new_smi->thread = kthread_run(ipmi_thread, new_smi,
					      "kipmi%d", new_smi->si_num);
		if (IS_ERR(new_smi->thread)) {
			dev_notice(new_smi->io.dev, "Could not start"
				   " kernel thread due to error %ld, only using"
				   " timers to drive the interface\n",
				   PTR_ERR(new_smi->thread));
			new_smi->thread = NULL;
		}
	}

	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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.