RE: [PATCH v7 2/3] scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening

[Michael Kelley]

From: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx> Sent: Monday, September 7, 2020 9:19 AM
> 
> From: Andres Beltran <lkmlabelt@xxxxxxxxx>
> 
> Currently, pointers to guest memory are passed to Hyper-V as
> transaction IDs in storvsc. In the face of errors or malicious
> behavior in Hyper-V, storvsc 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.
> 
> 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>
> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
> Cc: linux-scsi@xxxxxxxxxxxxxxx
> ---
> Changes in v7:
> 	- Move the allocation of the request ID after the data has been
> 	  copied into the ring buffer (cf. 1/3).
> Changes in v2:
>         - Add casts to unsigned long to fix warnings on 32bit.
> 
>  drivers/scsi/storvsc_drv.c | 26 +++++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 

Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>