[v1,0/2] virtio: Add length checks for device writable portions

Message

Max Gurtovoy Feb. 24, 2025, 11:31 p.m. UTC

Hi,

This patch series introduces safety checks in virtio-blk and virtio-fs
drivers to ensure proper handling of device-writable buffer lengths as
specified by the virtio specification.

The virtio specification states:
"The driver MUST NOT make assumptions about data in device-writable
buffers beyond the first len bytes, and SHOULD ignore this data."

To align with this requirement, we introduce checks in both drivers to
verify that the length of data written by the device is at least as
large as the expected/needed payload.

If this condition is not met, we set an I/O error status to prevent
processing of potentially invalid or incomplete data.

These changes improve the robustness of the drivers and ensure better
compliance with the virtio specification.

Max Gurtovoy (2):
  virtio_blk: add length check for device writable portion
  virtio_fs: add length check for device writable portion

 drivers/block/virtio_blk.c | 20 ++++++++++++++++++++
 fs/fuse/virtio_fs.c        |  9 +++++++++
 2 files changed, 29 insertions(+)