Re: [Qemu-devel] [PATCH 2/2] cadence_gem: avoid stack-writing buffer-overrun

[Stefan Weil]

Am 14.05.2012 06:57, schrieb Peter Crosthwaite:
> ACK and Thanks Jim,
>
> Reviewed-by: Peter A.G. Crosthwaite<address@hidden>
>
> On Fri, May 11, 2012 at 2:19 AM, Jim Meyering<address@hidden>  wrote:
>    
> > From: Jim Meyering<address@hidden>
> >
> > Use sizeof(rxbuf)-size (not sizeof(rxbuf-size)) as the number
> > of bytes to clear.  The latter would always clear 4 or 8
> > bytes, possibly writing beyond the end of that stack buffer.
> > Alternatively, depending on the value of the "size" parameter,
> > it could fail to initialize the end of "rxbuf".
> > Spotted by coverity.
> >
> > Signed-off-by: Jim Meyering<address@hidden>
> > ---
> >   hw/cadence_gem.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/cadence_gem.c b/hw/cadence_gem.c
> > index e2140ae..dbde392 100644
> > --- a/hw/cadence_gem.c
> > +++ b/hw/cadence_gem.c
> > @@ -664,7 +664,7 @@ static ssize_t gem_receive(VLANClientState *nc, const 
> > uint8_t *buf, size_t size)
> >           */
> >
> >          memcpy(rxbuf, buf, size);
> > -        memset(rxbuf + size, 0, sizeof(rxbuf - size));
> > +        memset(rxbuf + size, 0, sizeof(rxbuf) - size);
> >          rxbuf_ptr = rxbuf;
> >          crc_val = cpu_to_le32(crc32(0, rxbuf, MAX(size, 60)));
> >          if (size<  60) {
> > --
> > 1.7.10.1.487.ga3935e6
> >      


Ping. This patch is still missing in 1.1 and master.