Re: [Qemu-stable] [Qemu-devel] [PATCH 4/4] net: ignore packet size greater than INT_MAX

[Jason Wang]

On 2018年09月25日 22:15, Michael S. Tsirkin wrote:
> On Tue, Sep 25, 2018 at 03:23:27PM +0800, Jason Wang wrote:
> > There should not be a reason for passing a packet size greater than
> > INT_MAX. It's usually a hint of bug somewhere, so ignore packet size
> > greater than INT_MAX in qemu_deliver_packet_iov()
> >
> > CC: address@hidden
> > Reported-by: Daniel Shapira <address@hidden>
> > Signed-off-by: Jason Wang <address@hidden>
> > ---
> >   net/net.c | 7 ++++++-
> >   1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/net.c b/net/net.c
> > index fd8efebfdb..df216e3811 100644
> > --- a/net/net.c
> > +++ b/net/net.c
> > @@ -712,10 +712,15 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender,
> >                                   void *opaque)
> >   {
> >       NetClientState *nc = opaque;
> > +    size_t size = iov_size(iov, iovcnt);
> >       int ret;
> >   
> This adds a useless iov scan on the good path.
> Can't be good for performance...

Yes, will consider some optimization in the future.

Thanks

> > +    if (size > INT_MAX) {
> > +        return size;
> > +    }
> > +
> >       if (nc->link_down) {
> > -        return iov_size(iov, iovcnt);
> > +        return size;
> >       }
> >   
> >       if (nc->receive_disabled) {
> > --
> > 2.17.1