int sr_get_mcn(struct cdrom_device_info *cdi, struct cdrom_mcn *mcn)
{
	Scsi_CD *cd = cdi->handle;
	struct packet_command cgc;
	char *buffer = kmalloc(32, GFP_KERNEL | SR_GFP_DMA(cd));
	int result;

	if (!buffer)
		return -ENOMEM;

	memset(&cgc, 0, sizeof(struct packet_command));
	cgc.cmd[0] = GPCMD_READ_SUBCHANNEL;
	cgc.cmd[2] = 0x40;	/* I do want the subchannel info */
	cgc.cmd[3] = 0x02;	/* Give me medium catalog number info */
	cgc.cmd[8] = 24;
	cgc.buffer = buffer;
	cgc.buflen = 24;
	cgc.data_direction = DMA_FROM_DEVICE;
	cgc.timeout = IOCTL_TIMEOUT;
	result = sr_do_ioctl(cd, &cgc);

	memcpy(mcn->medium_catalog_number, buffer + 9, 13);
	mcn->medium_catalog_number[13] = 0;

	kfree(buffer);
	return result;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.