Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> writes:
> To reach the data region, the existing code adds offset in struct
> nvsp_5_send_indirect_table on the beginning of this struct. But the
> offset should be based on the beginning of its container,
> struct nvsp_message. This bug causes the first table entry missing,
> and adds an extra zero from the zero pad after the data region.
> This can put extra burden on the channel 0.
>
> So, correct the offset usage. Also add a boundary check to ensure
> not reading beyond data region.
>
> Fixes: 5b54dac856cb ("hyperv: Add support for virtual Receive Side Scaling (vRSS)")
> Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> ---
> drivers/net/hyperv/hyperv_net.h | 3 ++-
> drivers/net/hyperv/netvsc.c | 26 ++++++++++++++++++--------
> 2 files changed, 20 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
> index 670ef68..fb547f3 100644
> --- a/drivers/net/hyperv/hyperv_net.h
> +++ b/drivers/net/hyperv/hyperv_net.h
> @@ -609,7 +609,8 @@ struct nvsp_5_send_indirect_table {
> /* The number of entries in the send indirection table */
> u32 count;
>
> - /* The offset of the send indirection table from top of this struct.
> + /* The offset of the send indirection table from the beginning of
> + * struct nvsp_message.
> * The send indirection table tells which channel to put the send
> * traffic on. Each entry is a channel number.
> */
> diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
> index d22a36f..efd30e2 100644
> --- a/drivers/net/hyperv/netvsc.c
> +++ b/drivers/net/hyperv/netvsc.c
> @@ -1178,20 +1178,28 @@ static int netvsc_receive(struct net_device *ndev,
> }
>
> static void netvsc_send_table(struct net_device *ndev,
> - const struct nvsp_message *nvmsg)
> + const struct nvsp_message *nvmsg,
> + u32 msglen)
> {
> struct net_device_context *net_device_ctx = netdev_priv(ndev);
> - u32 count, *tab;
> + u32 count, offset, *tab;
> int i;
>
> count = nvmsg->msg.v5_msg.send_table.count;
> + offset = nvmsg->msg.v5_msg.send_table.offset;
> +
> if (count != VRSS_SEND_TAB_SIZE) {
> netdev_err(ndev, "Received wrong send-table size:%u\n", count);
> return;
> }
>
> - tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
> - nvmsg->msg.v5_msg.send_table.offset);
> + if (offset + count * sizeof(u32) > msglen) {
Nit: I think this can overflow.
> + netdev_err(ndev, "Received send-table offset too big:%u\n",
> + offset);
> + return;
> + }
> +
> + tab = (void *)nvmsg + offset;
But tab is 'u32 *', doesn't compiler complain?
>
> for (i = 0; i < count; i++)
> net_device_ctx->tx_table[i] = tab[i];
> @@ -1209,12 +1217,13 @@ static void netvsc_send_vf(struct net_device *ndev,
> net_device_ctx->vf_alloc ? "added" : "removed");
> }
>
> -static void netvsc_receive_inband(struct net_device *ndev,
> - const struct nvsp_message *nvmsg)
> +static void netvsc_receive_inband(struct net_device *ndev,
> + const struct nvsp_message *nvmsg,
> + u32 msglen)
> {
> switch (nvmsg->hdr.msg_type) {
> case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
> - netvsc_send_table(ndev, nvmsg);
> + netvsc_send_table(ndev, nvmsg, msglen);
> break;
>
> case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
> @@ -1232,6 +1241,7 @@ static int netvsc_process_raw_pkt(struct hv_device *device,
> {
> struct vmbus_channel *channel = nvchan->channel;
> const struct nvsp_message *nvmsg = hv_pkt_data(desc);
> + u32 msglen = hv_pkt_datalen(desc);
>
> trace_nvsp_recv(ndev, channel, nvmsg);
>
> @@ -1247,7 +1257,7 @@ static int netvsc_process_raw_pkt(struct hv_device *device,
> break;
>
> case VM_PKT_DATA_INBAND:
> - netvsc_receive_inband(ndev, nvmsg);
> + netvsc_receive_inband(ndev, nvmsg, msglen);
> break;
>
> default:
--
Vitaly
