On Tue, Jan 26, 2021 at 11:32:37AM -0800, wuhaotsh--- via wrote: > + > +static void npcm7xx_smbus_read_byte_fifo(NPCM7xxSMBusState *s) > +{ > + uint8_t received_bytes = NPCM7XX_SMBRXF_STS_RX_BYTES(s->rxf_sts); > + > + if (received_bytes == 0) { > + npcm7xx_smbus_recv_fifo(s); > + return; > + } > + > + s->sda = s->rx_fifo[s->rx_cur]; > + s->rx_cur = (s->rx_cur + 1u) % NPCM7XX_SMBUS_FIFO_SIZE; > + --s->rxf_sts;
This open-coded decrement seems a little risky. Are you sure in every case that s->rxf_sts > 0? There's no way what's running in the VM can game this and cause a buffer overrun? One caller to this function seems to protect against this, and another does not. Other than this, I didn't see any issues with this patch. -corey