[PATCH v7 0/3] Drivers: hv: vmbus: vmbus_requestor data structure for VMBus hardening

[Andrea Parri (Microsoft)]

Currently, VMbus drivers use pointers into guest memory as request IDs
for interactions with Hyper-V. To be more robust in the face of errors
or malicious behavior from a compromised Hyper-V, avoid exposing
guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a
bad request ID that is then treated as the address of a guest data
structure with no validation. Instead, encapsulate these memory
addresses and provide small integers as request IDs.

The first patch creates the definitions for the data structure, provides
helper methods to generate new IDs and retrieve data, and
allocates/frees the memory needed for vmbus_requestor.

The second and third patches make use of vmbus_requestor to send request
IDs to Hyper-V in storvsc and netvsc respectively.

This version of the series moves the allocation of the requst ID after
the data has been copied into the ring buffer in hv_ringbuffer_write()
to address a race with the request completion path pointed out by Juan.

  Andrea

Cc: James E.J. Bottomley <jejb@xxxxxxxxxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: linux-scsi@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx

Andres Beltran (3):
  Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus
    hardening
  scsi: storvsc: Use vmbus_requestor to generate transaction IDs for
    VMBus hardening
  hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus
    hardening

 drivers/hv/channel.c              | 174 ++++++++++++++++++++++++++++--
 drivers/hv/hyperv_vmbus.h         |   3 +-
 drivers/hv/ring_buffer.c          |  28 ++++-
 drivers/net/hyperv/hyperv_net.h   |  13 +++
 drivers/net/hyperv/netvsc.c       |  22 ++--
 drivers/net/hyperv/rndis_filter.c |   1 +
 drivers/scsi/storvsc_drv.c        |  26 ++++-
 include/linux/hyperv.h            |  23 ++++
 8 files changed, 272 insertions(+), 18 deletions(-)

-- 
2.25.1