RE: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity.
> -Original Message- > From: Peter Maydell > Sent: Friday, August 5, 2022 4:53 PM > To: Zhang, Chen > Cc: Jason Wang ; Li Zhijian ; > qemu-dev > Subject: Re: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity. > > On Fri, 5 Aug 2022 at 06:56, Zhang, Chen wrote: > > > > > > > > > -Original Message- > > > From: Jason Wang I wonder under which case > we > > > can see data == NULL? > > > > > > AFAIK, data is either dup via packet_new() or assigned to a pointer > > > to the buf in packet_new_nocopy(). > > > > Yes, you are right. I just checked it for hint of bugs. > > Do you think no need to do it? > > If you think it is a "should never happen unless QEMU is buggy" case, then > assert(data). OK, I will change it to assert() in V2. Thanks Chen > > thanks > -- PMM
Re: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity.
On Fri, 5 Aug 2022 at 06:56, Zhang, Chen wrote: > > > > > -Original Message- > > From: Jason Wang > > I wonder under which case we can see data == NULL? > > > > AFAIK, data is either dup via packet_new() or assigned to a pointer to the > > buf > > in packet_new_nocopy(). > > Yes, you are right. I just checked it for hint of bugs. > Do you think no need to do it? If you think it is a "should never happen unless QEMU is buggy" case, then assert(data). thanks -- PMM
RE: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity.
> -Original Message-
> From: Jason Wang
> Sent: Friday, August 5, 2022 11:46 AM
> To: Zhang, Chen
> Cc: Peter Maydell ; Li Zhijian
> ; qemu-dev
> Subject: Re: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity.
>
> On Tue, Aug 2, 2022 at 4:24 PM Zhang Chen wrote:
> >
> > When enable the virtio-net-pci, guest network packet will load the
> > vnet_hdr. In COLO status, the primary VM's network packet maybe
> > redirect to another VM, it need filter-redirect enable the vnet_hdr
> > flag at the same time, COLO-proxy will correctly parse the original
> > network packet. If have any misconfiguration here, the vnet_hdr_len is
> > wrong for parse the packet, the data+offset will point to wrong place.
> >
> > Signed-off-by: Zhang Chen
> > ---
> > net/colo.c | 16 ++--
> > 1 file changed, 10 insertions(+), 6 deletions(-)
> >
> > diff --git a/net/colo.c b/net/colo.c
> > index 6b0ff562ad..dfb15b4c14 100644
> > --- a/net/colo.c
> > +++ b/net/colo.c
> > @@ -44,21 +44,25 @@ int parse_packet_early(Packet *pkt) {
> > int network_length;
> > static const uint8_t vlan[] = {0x81, 0x00};
> > -uint8_t *data = pkt->data + pkt->vnet_hdr_len;
> > +uint8_t *data = pkt->data;
> > uint16_t l3_proto;
> > ssize_t l2hdr_len;
> >
> > if (data == NULL) {
>
> I wonder under which case we can see data == NULL?
>
> AFAIK, data is either dup via packet_new() or assigned to a pointer to the buf
> in packet_new_nocopy().
Yes, you are right. I just checked it for hint of bugs.
Do you think no need to do it?
Thanks
Chen
>
> Thanks
>
> > -trace_colo_proxy_main_vnet_info("This packet is not parsed
> > correctly,
> "
> > -"pkt->vnet_hdr_len",
> > pkt->vnet_hdr_len);
> > +trace_colo_proxy_main("COLO-proxy got NULL data packet ");
> > return 1;
> > }
> > -l2hdr_len = eth_get_l2_hdr_length(data);
> >
> > -if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) {
> > -trace_colo_proxy_main("pkt->size < ETH_HLEN");
> > +/* Check the received vnet_hdr_len then add the offset */
> > +if (pkt->size < sizeof(struct eth_header) + sizeof(struct vlan_header)
> > ++ pkt->vnet_hdr_len) {
> > +trace_colo_proxy_main_vnet_info("This packet may be load wrong "
> > +"pkt->vnet_hdr_len",
> > + pkt->vnet_hdr_len);
> > return 1;
> > }
> > +data += pkt->vnet_hdr_len;
> > +
> > +l2hdr_len = eth_get_l2_hdr_length(data);
> >
> > /*
> > * TODO: support vlan.
> > --
> > 2.25.1
> >
Re: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity.
On Tue, Aug 2, 2022 at 4:24 PM Zhang Chen wrote:
>
> When enable the virtio-net-pci, guest network packet will
> load the vnet_hdr. In COLO status, the primary VM's network
> packet maybe redirect to another VM, it need filter-redirect
> enable the vnet_hdr flag at the same time, COLO-proxy will
> correctly parse the original network packet. If have any
> misconfiguration here, the vnet_hdr_len is wrong for parse
> the packet, the data+offset will point to wrong place.
>
> Signed-off-by: Zhang Chen
> ---
> net/colo.c | 16 ++--
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/net/colo.c b/net/colo.c
> index 6b0ff562ad..dfb15b4c14 100644
> --- a/net/colo.c
> +++ b/net/colo.c
> @@ -44,21 +44,25 @@ int parse_packet_early(Packet *pkt)
> {
> int network_length;
> static const uint8_t vlan[] = {0x81, 0x00};
> -uint8_t *data = pkt->data + pkt->vnet_hdr_len;
> +uint8_t *data = pkt->data;
> uint16_t l3_proto;
> ssize_t l2hdr_len;
>
> if (data == NULL) {
I wonder under which case we can see data == NULL?
AFAIK, data is either dup via packet_new() or assigned to a pointer to
the buf in packet_new_nocopy().
Thanks
> -trace_colo_proxy_main_vnet_info("This packet is not parsed
> correctly, "
> -"pkt->vnet_hdr_len",
> pkt->vnet_hdr_len);
> +trace_colo_proxy_main("COLO-proxy got NULL data packet ");
> return 1;
> }
> -l2hdr_len = eth_get_l2_hdr_length(data);
>
> -if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) {
> -trace_colo_proxy_main("pkt->size < ETH_HLEN");
> +/* Check the received vnet_hdr_len then add the offset */
> +if (pkt->size < sizeof(struct eth_header) + sizeof(struct vlan_header)
> ++ pkt->vnet_hdr_len) {
> +trace_colo_proxy_main_vnet_info("This packet may be load wrong "
> +"pkt->vnet_hdr_len",
> pkt->vnet_hdr_len);
> return 1;
> }
> +data += pkt->vnet_hdr_len;
> +
> +l2hdr_len = eth_get_l2_hdr_length(data);
>
> /*
> * TODO: support vlan.
> --
> 2.25.1
>
