| Message ID | 20220802080948.37426-1-chen.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | net/colo.c: Fix the pointer issuse reported by Coverity. | expand |
On Tue, Aug 2, 2022 at 4:24 PM Zhang Chen <chen.zhang@intel.com> 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 <chen.zhang@intel.com> > --- > 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 >
> -----Original Message----- > From: Jason Wang <jasowang@redhat.com> > Sent: Friday, August 5, 2022 11:46 AM > To: Zhang, Chen <chen.zhang@intel.com> > Cc: Peter Maydell <peter.maydell@linaro.org>; Li Zhijian > <lizhijian@fujitsu.com>; qemu-dev <qemu-devel@nongnu.org> > Subject: Re: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity. > > On Tue, Aug 2, 2022 at 4:24 PM Zhang Chen <chen.zhang@intel.com> 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 <chen.zhang@intel.com> > > --- > > 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 > >
On Fri, 5 Aug 2022 at 06:56, Zhang, Chen <chen.zhang@intel.com> wrote: > > > > > -----Original Message----- > > From: Jason Wang <jasowang@redhat.com> > > 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
> -----Original Message----- > From: Peter Maydell <peter.maydell@linaro.org> > Sent: Friday, August 5, 2022 4:53 PM > To: Zhang, Chen <chen.zhang@intel.com> > Cc: Jason Wang <jasowang@redhat.com>; Li Zhijian <lizhijian@fujitsu.com>; > qemu-dev <qemu-devel@nongnu.org> > Subject: Re: [PATCH] net/colo.c: Fix the pointer issuse reported by Coverity. > > On Fri, 5 Aug 2022 at 06:56, Zhang, Chen <chen.zhang@intel.com> wrote: > > > > > > > > > -----Original Message----- > > > From: Jason Wang <jasowang@redhat.com> 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
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) { - 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.
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 <chen.zhang@intel.com> --- net/colo.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)