static int try_enable_event_buffer(struct smi_info *smi_info)
{
	unsigned char         msg[3];
	unsigned char         *resp;
	unsigned long         resp_len;
	int                   rv = 0;

	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
	if (!resp)
		return -ENOMEM;

	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
	smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);

	rv = wait_for_msg_done(smi_info);
	if (rv) {
		pr_warn("Error getting response from get global enables command, the event buffer is not enabled\n");
		goto out;
	}

	resp_len = smi_info->handlers->get_result(smi_info->si_sm,
						  resp, IPMI_MAX_MSG_LENGTH);

	if (resp_len < 4 ||
			resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
			resp[1] != IPMI_GET_BMC_GLOBAL_ENABLES_CMD   ||
			resp[2] != 0) {
		pr_warn("Invalid return from get global enables command, cannot enable the event buffer\n");
		rv = -EINVAL;
		goto out;
	}

	if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
		/* buffer is already enabled, nothing to do. */
		smi_info->supports_event_msg_buff = true;
		goto out;
	}

	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
	msg[2] = resp[3] | IPMI_BMC_EVT_MSG_BUFF;
	smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);

	rv = wait_for_msg_done(smi_info);
	if (rv) {
		pr_warn("Error getting response from set global, enables command, the event buffer is not enabled\n");
		goto out;
	}

	resp_len = smi_info->handlers->get_result(smi_info->si_sm,
						  resp, IPMI_MAX_MSG_LENGTH);

	if (resp_len < 3 ||
			resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
			resp[1] != IPMI_SET_BMC_GLOBAL_ENABLES_CMD) {
		pr_warn("Invalid return from get global, enables command, not enable the event buffer\n");
		rv = -EINVAL;
		goto out;
	}

	if (resp[2] != 0)
		/*
		 * An error when setting the event buffer bit means
		 * that the event buffer is not supported.
		 */
		rv = -ENOENT;
	else
		smi_info->supports_event_msg_buff = true;

out:
	kfree(resp);
	return rv;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.