static inline u32 tg3_tx_avail(struct tg3_napi *tnapi)
{
	/* Tell compiler to fetch tx indices from memory. */
	barrier();
	return tnapi->tx_pending -
	       ((tnapi->tx_prod - tnapi->tx_cons) & (TG3_TX_RING_SIZE - 1));
}

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.