static irqreturn_t tg3_interrupt(int irq, void *dev_id)
{
	struct tg3_napi *tnapi = dev_id;
	struct tg3 *tp = tnapi->tp;
	struct tg3_hw_status *sblk = tnapi->hw_status;
	unsigned int handled = 1;

	/* In INTx mode, it is possible for the interrupt to arrive at
	 * the CPU before the status block posted prior to the interrupt.
	 * Reading the PCI State register will confirm whether the
	 * interrupt is ours and will flush the status block.
	 */
	if (unlikely(!(sblk->status & SD_STATUS_UPDATED))) {
		if (tg3_flag(tp, CHIP_RESETTING) ||
		    (tr32(TG3PCI_PCISTATE) & PCISTATE_INT_NOT_ACTIVE)) {
			handled = 0;
			goto out;
		}
	}

	/*
	 * Writing any value to intr-mbox-0 clears PCI INTA# and
	 * chip-internal interrupt pending events.
	 * Writing non-zero to intr-mbox-0 additional tells the
	 * NIC to stop sending us irqs, engaging "in-intr-handler"
	 * event coalescing.
	 *
	 * Flush the mailbox to de-assert the IRQ immediately to prevent
	 * spurious interrupts.  The flush impacts performance but
	 * excessive spurious interrupts can be worse in some cases.
	 */
	tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000001);
	if (tg3_irq_sync(tp))
		goto out;
	sblk->status &= ~SD_STATUS_UPDATED;
	if (likely(tg3_has_work(tnapi))) {
		prefetch(&tnapi->rx_rcb[tnapi->rx_rcb_ptr]);
		napi_schedule(&tnapi->napi);
	} else {
		/* No work, shared interrupt perhaps?  re-enable
		 * interrupts, and flush that PCI write
		 */
		tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
			       0x00000000);
	}
out:
	return IRQ_RETVAL(handled);
}

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.