RE: [PATCH v4] hv_utils: Add validation for untrusted Hyper-V values

[Michael Kelley]

From: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx> Sent: Monday, November 9, 2020 2:07 AM
> 
> For additional robustness in the face of Hyper-V errors or malicious
> behavior, validate all values that originate from packets that Hyper-V
> has sent to the guest in the host-to-guest ring buffer. Ensure that
> invalid values cannot cause indexing off the end of the icversion_data
> array in vmbus_prep_negotiate_resp().
> 
> Signed-off-by: Andres Beltran <lkmlabelt@xxxxxxxxx>
> Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
> ---
> Changes in v3:
> 	- Add size check for icframe_vercnt and icmsg_vercnt
> 
> Changes in v2:
> 	- Use ratelimited form of kernel logging to print error messages
> 
>  drivers/hv/channel_mgmt.c |  24 ++++-
>  drivers/hv/hv_fcopy.c     |  36 +++++--
>  drivers/hv/hv_kvp.c       | 122 ++++++++++++---------
>  drivers/hv/hv_snapshot.c  |  89 ++++++++-------
>  drivers/hv/hv_util.c      | 222 +++++++++++++++++++++++---------------
>  include/linux/hyperv.h    |   9 +-
>  6 files changed, 314 insertions(+), 188 deletions(-)
> 

Reviewed-by:  Michael Kelley <mikelley@xxxxxxxxxxxxx>