static void b43_poison_rx_buffer(struct b43_dmaring *ring, struct sk_buff *skb)
{
	struct b43_rxhdr_fw4 *rxhdr;
	unsigned char *frame;

	/* This poisons the RX buffer to detect DMA failures. */

	rxhdr = (struct b43_rxhdr_fw4 *)(skb->data);
	rxhdr->frame_len = 0;

	B43_WARN_ON(ring->rx_buffersize < ring->frameoffset + sizeof(struct b43_plcp_hdr6) + 2);
	frame = skb->data + ring->frameoffset;
	memset(frame, 0xFF, sizeof(struct b43_plcp_hdr6) + 2 /* padding */);
}

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.