static int dmacontroller_setup(struct b43_dmaring *ring)
{
	int err = 0;
	u32 value;
	u32 addrext;
	u32 trans = ssb_dma_translation(ring->dev->dev);

	if (ring->tx) {
		if (ring->type == B43_DMA_64BIT) {
			u64 ringbase = (u64) (ring->dmabase);

			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
			    >> SSB_DMA_TRANSLATION_SHIFT;
			value = B43_DMA64_TXENABLE;
			value |= (addrext << B43_DMA64_TXADDREXT_SHIFT)
			    & B43_DMA64_TXADDREXT_MASK;
			b43_dma_write(ring, B43_DMA64_TXCTL, value);
			b43_dma_write(ring, B43_DMA64_TXRINGLO,
				      (ringbase & 0xFFFFFFFF));
			b43_dma_write(ring, B43_DMA64_TXRINGHI,
				      ((ringbase >> 32) &
				       ~SSB_DMA_TRANSLATION_MASK)
				      | (trans << 1));
		} else {
			u32 ringbase = (u32) (ring->dmabase);

			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
			    >> SSB_DMA_TRANSLATION_SHIFT;
			value = B43_DMA32_TXENABLE;
			value |= (addrext << B43_DMA32_TXADDREXT_SHIFT)
			    & B43_DMA32_TXADDREXT_MASK;
			b43_dma_write(ring, B43_DMA32_TXCTL, value);
			b43_dma_write(ring, B43_DMA32_TXRING,
				      (ringbase & ~SSB_DMA_TRANSLATION_MASK)
				      | trans);
		}
	} else {
		err = alloc_initial_descbuffers(ring);
		if (err)
			goto out;
		if (ring->type == B43_DMA_64BIT) {
			u64 ringbase = (u64) (ring->dmabase);

			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
			    >> SSB_DMA_TRANSLATION_SHIFT;
			value = (ring->frameoffset << B43_DMA64_RXFROFF_SHIFT);
			value |= B43_DMA64_RXENABLE;
			value |= (addrext << B43_DMA64_RXADDREXT_SHIFT)
			    & B43_DMA64_RXADDREXT_MASK;
			b43_dma_write(ring, B43_DMA64_RXCTL, value);
			b43_dma_write(ring, B43_DMA64_RXRINGLO,
				      (ringbase & 0xFFFFFFFF));
			b43_dma_write(ring, B43_DMA64_RXRINGHI,
				      ((ringbase >> 32) &
				       ~SSB_DMA_TRANSLATION_MASK)
				      | (trans << 1));
			b43_dma_write(ring, B43_DMA64_RXINDEX, ring->nr_slots *
				      sizeof(struct b43_dmadesc64));
		} else {
			u32 ringbase = (u32) (ring->dmabase);

			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
			    >> SSB_DMA_TRANSLATION_SHIFT;
			value = (ring->frameoffset << B43_DMA32_RXFROFF_SHIFT);
			value |= B43_DMA32_RXENABLE;
			value |= (addrext << B43_DMA32_RXADDREXT_SHIFT)
			    & B43_DMA32_RXADDREXT_MASK;
			b43_dma_write(ring, B43_DMA32_RXCTL, value);
			b43_dma_write(ring, B43_DMA32_RXRING,
				      (ringbase & ~SSB_DMA_TRANSLATION_MASK)
				      | trans);
			b43_dma_write(ring, B43_DMA32_RXINDEX, ring->nr_slots *
				      sizeof(struct b43_dmadesc32));
		}
	}

out:
	return err;
}

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.