static void fwnet_receive_broadcast(struct fw_iso_context *context,
		u32 cycle, size_t header_length, void *header, void *data)
{
	struct fwnet_device *dev;
	struct fw_iso_packet packet;
	__be16 *hdr_ptr;
	__be32 *buf_ptr;
	int retval;
	u32 length;
	unsigned long offset;
	unsigned long flags;

	dev = data;
	hdr_ptr = header;
	length = be16_to_cpup(hdr_ptr);

	spin_lock_irqsave(&dev->lock, flags);

	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
		dev->broadcast_rcv_next_ptr = 0;

	spin_unlock_irqrestore(&dev->lock, flags);

	if (length > IEEE1394_GASP_HDR_SIZE &&
	    gasp_specifier_id(buf_ptr) == IANA_SPECIFIER_ID &&
	    (gasp_version(buf_ptr) == RFC2734_SW_VERSION
#if IS_ENABLED(CONFIG_IPV6)
	     || gasp_version(buf_ptr) == RFC3146_SW_VERSION
#endif
	    ))
		fwnet_incoming_packet(dev, buf_ptr + 2,
				      length - IEEE1394_GASP_HDR_SIZE,
				      gasp_source_id(buf_ptr),
				      context->card->generation, true);

	packet.payload_length = dev->rcv_buffer_size;
	packet.interrupt = 1;
	packet.skip = 0;
	packet.tag = 3;
	packet.sy = 0;
	packet.header_length = IEEE1394_GASP_HDR_SIZE;

	spin_lock_irqsave(&dev->lock, flags);

	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
				      &dev->broadcast_rcv_buffer, offset);

	spin_unlock_irqrestore(&dev->lock, flags);

	if (retval >= 0)
		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
	else
		dev_err(&dev->netdev->dev, "requeue failed\n");
}
The software performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer.