> -----Original Message-----
> From: Andres Beltran <lkmlab...@gmail.com>
> Sent: Thursday, June 25, 2020 11:37 AM
> To: KY Srinivasan <k...@microsoft.com>; Haiyang Zhang
> <haiya...@microsoft.com>; Stephen Hemminger <sthem...@microsoft.com>;
> wei....@kernel.org
> Cc: linux-hyp...@vger.kernel.org; linux-kernel@vger.kernel.org; Michael
> Kelley <mikel...@microsoft.com>; parri.and...@gmail.com; Andres Beltran
> <lkmlab...@gmail.com>; David S. Miller <da...@davemloft.net>; Jakub
> Kicinski <k...@kernel.org>; net...@vger.kernel.org
> Subject: [PATCH 3/3] hv_netvsc: Use vmbus_requestor to generate transaction
> IDs for VMBus hardening
>
> Currently, pointers to guest memory are passed to Hyper-V as
> transaction IDs in netvsc. In the face of errors or malicious
> behavior in Hyper-V, netvsc should not expose or trust the transaction
> IDs returned by Hyper-V to be valid guest memory addresses. Instead,
> use small integers generated by vmbus_requestor as requests
> (transaction) IDs.
>
> Cc: "David S. Miller" <da...@davemloft.net>
> Cc: Jakub Kicinski <k...@kernel.org>
> Cc: net...@vger.kernel.org
> Signed-off-by: Andres Beltran <lkmlab...@gmail.com>
> ---
> drivers/net/hyperv/hyperv_net.h | 10 +++++
> drivers/net/hyperv/netvsc.c | 75 +++++++++++++++++++++++++------
> drivers/net/hyperv/rndis_filter.c | 1 +
> include/linux/hyperv.h | 1 +
> 4 files changed, 73 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
> index abda736e7c7d..14735c98e798 100644
> --- a/drivers/net/hyperv/hyperv_net.h
> +++ b/drivers/net/hyperv/hyperv_net.h
> @@ -847,6 +847,16 @@ struct nvsp_message {
>
> #define NETVSC_XDP_HDRM 256
>
> +#define NETVSC_MIN_OUT_MSG_SIZE (sizeof(struct vmpacket_descriptor) + \
> + sizeof(struct nvsp_message))
> +#define NETVSC_MIN_IN_MSG_SIZE sizeof(struct vmpacket_descriptor)
> +
> +/* Estimated requestor size:
> + * out_ring_size/min_out_msg_size + in_ring_size/min_in_msg_size
> + */
> +#define NETVSC_RQSTOR_SIZE (netvsc_ring_bytes /
> NETVSC_MIN_OUT_MSG_SIZE + \
> + netvsc_ring_bytes / NETVSC_MIN_IN_MSG_SIZE)
Please make the variable as the macro parameter for readability:
#define NETVSC_RQSTOR_SIZE(ringbytes) (ringbytes / NETVSC_MIN_OUT_MSG_SIZE ...
Then put the actual variable name when you use the macro.
Thanks,
- Haiyang
