[RFC PATCH 00/17] Add validation for used length

[Xie Yongji]

Current virtio device drivers may trust the used length returned
in virtqueue_get_buf()/virtqueue_get_buf_ctx(). But the used length
might come from an untrusted device when VDUSE[1] is enabled. To
protect this case, this series tries to add validation for the
used length.

Since many legacy devices will also set the used length incorrectly,
we did not add the validation unconditionally. Instead, we will do
the validation only when the device driver needs the used length.
A NULL len passed to virtqueue_get_buf()/virtqueue_get_buf_ctx()
will mean the used length is not needed by the device driver.

[1] https://lore.kernel.org/kvm/20210331080519.172-1-xieyongji@xxxxxxxxxxxxx/

Xie Yongji (17):
  virtio_ring: Avoid reading unneeded used length
  virtio-blk: Remove unused used length
  virtio_console: Remove unused used length
  crypto: virtio - Remove unused used length
  drm/virtio: Remove unused used length
  caif_virtio: Remove unused used length
  virtio_net: Remove unused used length
  mac80211_hwsim: Remove unused used length
  virtio_pmem: Remove unused used length
  rpmsg: virtio: Remove unused used length
  virtio_scsi: Remove unused used length
  virtio_balloon: Remove unused used length
  virtio_input: Remove unused used length
  virtio_mem: Remove unused used length
  virtiofs: Remove unused used length
  vsock: Remove unused used length
  virtio_ring: Add validation for used length

 drivers/block/virtio_blk.c                 |  3 +--
 drivers/char/virtio_console.c              | 12 ++++--------
 drivers/crypto/virtio/virtio_crypto_algs.c |  6 ++----
 drivers/gpu/drm/virtio/virtgpu_vq.c        |  3 +--
 drivers/net/caif/caif_virtio.c             |  3 +--
 drivers/net/virtio_net.c                   | 10 ++++------
 drivers/net/wireless/mac80211_hwsim.c      |  3 +--
 drivers/nvdimm/nd_virtio.c                 |  3 +--
 drivers/rpmsg/virtio_rpmsg_bus.c           |  3 +--
 drivers/scsi/virtio_scsi.c                 |  3 +--
 drivers/virtio/virtio_balloon.c            | 21 ++++++++++-----------
 drivers/virtio/virtio_input.c              |  6 ++----
 drivers/virtio/virtio_mem.c                |  3 +--
 drivers/virtio/virtio_ring.c               | 28 +++++++++++++++++++++++-----
 fs/fuse/virtio_fs.c                        |  6 ++----
 net/vmw_vsock/virtio_transport.c           |  3 +--
 16 files changed, 56 insertions(+), 60 deletions(-)

-- 
2.11.0