# Re: \[PATCH net-next\] hv\_netvsc: Copy packets sent by Hyper-V out of the receive buffer

- From: Andrea Parri \<parri.andrea@gmail.com\>
- Date: 2021-01-26 14:35:18 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/01/6247926
- Thread: https://ratatoskr.run/linux-hyperv/2021/01/6247618/t.md

```text
On Tue, Jan 26, 2021 at 12:38:47PM +0100, Andrea Parri (Microsoft) wrote:
> Pointers to receive-buffer packets sent by Hyper-V are used within the
> guest VM.  Hyper-V can send packets with erroneous values or modify
> packet fields after they are processed by the guest.  To defend against
> these scenarios, copy (sections of) the incoming packet after validating
> their length and offset fields in netvsc_filter_receive().  In this way,
> the packet can no longer be modified by the host.
> 
> Reported-by: Juan Vazquez <redacted>
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: <redacted>

Please ignore this submission, I'm sending a new version shortly...  Sorry for
the hassle.

  Andrea
```