Re: [Qemu-devel] [PATCH v2] net: mipsnet: check transmit buffer size before sending

[P J P]

  Hello Jason,

+-- On Mon, 13 Jun 2016, Jason Wang wrote --+
| >       case MIPSNET_TX_DATA_BUFFER:
| >           s->tx_buffer[s->tx_written++] = val;
| 
| I believe we may still have a buffer overflow here, no?

  No, this is the overflow that the patch is meant to fix.
 
| > -        if (s->tx_written == s->tx_count) {
| > +        if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
| > +            || (s->tx_written == s->tx_count)) {
| >               /* Send buffer. */

  Earlier, send buffer would occur when if 'tx_written' reached 'tx_count'. 
With this patch, it'll also occur when 'tx_written' reaches maximum frame 
size.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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