static void b43_destroy_dmaring(struct b43_dmaring *ring,
				const char *ringname)
{
	if (!ring)
		return;

#ifdef CONFIG_B43_DEBUG
	{
		/* Print some statistics. */
		u64 failed_packets = ring->nr_failed_tx_packets;
		u64 succeed_packets = ring->nr_succeed_tx_packets;
		u64 nr_packets = failed_packets + succeed_packets;
		u64 permille_failed = 0, average_tries = 0;

		if (nr_packets)
			permille_failed = divide(failed_packets * 1000, nr_packets);
		if (nr_packets)
			average_tries = divide(ring->nr_total_packet_tries * 100, nr_packets);

		b43dbg(ring->dev->wl, "DMA-%u %s: "
		       "Used slots %d/%d, Failed frames %llu/%llu = %llu.%01llu%%, "
		       "Average tries %llu.%02llu\n",
		       (unsigned int)(ring->type), ringname,
		       ring->max_used_slots,
		       ring->nr_slots,
		       (unsigned long long)failed_packets,
		       (unsigned long long)nr_packets,
		       (unsigned long long)divide(permille_failed, 10),
		       (unsigned long long)modulo(permille_failed, 10),
		       (unsigned long long)divide(average_tries, 100),
		       (unsigned long long)modulo(average_tries, 100));
	}
#endif /* DEBUG */

	/* Device IRQs are disabled prior entering this function,
	 * so no need to take care of concurrency with rx handler stuff.
	 */
	dmacontroller_cleanup(ring);
	free_all_descbuffers(ring);
	free_ringmemory(ring);

	kfree(ring->txhdr_cache);
	kfree(ring->meta);
	kfree(ring);
}

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.