static u64 supported_dma_mask(struct b43_wldev *dev)
{
	u32 tmp;
	u16 mmio_base;

	tmp = b43_read32(dev, SSB_TMSHIGH);
	if (tmp & SSB_TMSHIGH_DMA64)
		return DMA_BIT_MASK(64);
	mmio_base = b43_dmacontroller_base(0, 0);
	b43_write32(dev, mmio_base + B43_DMA32_TXCTL, B43_DMA32_TXADDREXT_MASK);
	tmp = b43_read32(dev, mmio_base + B43_DMA32_TXCTL);
	if (tmp & B43_DMA32_TXADDREXT_MASK)
		return DMA_BIT_MASK(32);

	return DMA_BIT_MASK(30);
}

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.