On 20/11/2014 06:57, arei.gong...@huawei.com wrote:
> From: Gonglei <arei.gong...@huawei.com>
>
> s->xmit_pos maybe assigned to a negative value (-1),
> but in this branch variable s->xmit_pos as an index to
> array s->buffer. Let's add a check for s->xmit_pos.
>
> Signed-off-by: Gonglei <arei.gong...@huawei.com>
> ---
> hw/net/pcnet.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
> index d344c15..2bb6417 100644
> --- a/hw/net/pcnet.c
> +++ b/hw/net/pcnet.c
> @@ -1247,7 +1247,7 @@ static void pcnet_transmit(PCNetState *s)
> s->xmit_pos = -1;
> goto txdone;
> }
> - if (!GET_FIELD(tmd.status, TMDS, ENP)) {
> + if (!GET_FIELD(tmd.status, TMDS, ENP) && (s->xmit_pos >= 0)) {
> int bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
> s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tbadr),
> s->buffer + s->xmit_pos, bcnt, CSR_BSWP(s));
>
Even better:
if (s->xmit_pos < 0) {
goto txdone;
}
bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tbadr),
s->buffer + s->xmit_pos, bcnt, CSR_BSWP(s));
s->xmit_pos += bcnt;
if (FIELD(tmd.status, TMDS, ENP)) {
#ifdef PCNET_DEBUG
printf("pcnet_transmit size=%d\n", s->xmit_pos);
#endif
if (CSR_LOOP(s)) {
if (BCR_SWSTYLE(s) == 1)
...
}
since there is duplicated code in the two "if" arms. But the call is
Stefan's, as he's the maintainer.
Paolo
