Re: [PATCH v4 00/34] modules: add meta-data database

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Gerd Hoffmann (kraxel@redhat.com) wrote:
> This patch series adds support for module meta-data.  Today this is
> either hard-coded in qemu (see qemu_load_module_for_opts) or handled
> with manually maintained lists in util/module (see module_deps[] and
> qom_modules[]).  This series replaced that scheme with annotation
> macros, so the meta-data can go into the module source code and -- for
> example -- the module_obj() annotations can go next to the TypeInfo
> struct for the object class.

So this is slightly off-topic for the series; but kind of relevant,
but...
Is there a way to inhibit module loading after a given point?

I ask, because there's a fairly well known security escalation that
takes advantage of NSS loading of PAM modules; typically you have
your nice sandboxed application, you write out your nasty .so into the
sandbox and then somehow get your application to trigger the PAM module
load.
Now, what stops the same attack here?

Dave

> Patches 1-3 put the infrastructure in place:  Add the annotation macros,
> add a script to collect the meta-data, add a script to compile the
> meta-data into C source code which we can then add to qemu.
> 
> Patch 4 - check module dependencies (Jose, new in v4).
> 
> Patches 5-13 add annotations macros to the modules we have.
> 
> Patches 14-16 put the modinfo database into use and remove the
> module_deps[] and qom_modules[] lists.
> 
> Patch 16 adds two tracepoints for easier trouble-shooting.
> 
> Patches 18-20 add support for target-specific modules.
> 
> Patches 21-24 add documentation for all of the above (new in v4, was
> separate series).
> 
> Patches 25-29 start building accelerators modular.  So far it is
> only qtest (all archs) and a small fraction of tcg (x86 only).
> 
> Patches 30-34 add support for registering hmp commands so they can
> be implemented as module (new in v4, was separate series).
> 
> take care,
>   Gerd
> 
> Gerd Hoffmann (33):
>   modules: add modinfo macros
>   modules: collect module meta-data
>   modules: generate modinfo.c
>   modules: add qxl module annotations
>   modules: add virtio-gpu module annotations
>   modules: add chardev module annotations
>   modules: add audio module annotations
>   modules: add usb-redir module annotations
>   modules: add ccid module annotations
>   modules: add ui module annotations
>   modules: add s390x module annotations
>   modules: add block module annotations
>   modules: use modinfo for dependencies
>   modules: use modinfo for qom load
>   modules: use modinfo for qemu opts load
>   modules: add tracepoints
>   modules: check arch and block load on mismatch
>   modules: check arch on qom lookup
>   modules: target-specific module build infrastructure
>   modules: add documentation for module sourcesets
>   modules: add module_obj() note to QOM docs
>   modules: module.h kerneldoc annotations
>   modules: hook up modules.h to docs build
>   accel: autoload modules
>   accel: add qtest module annotations
>   accel: build qtest modular
>   accel: add tcg module annotations
>   accel: build tcg modular
>   monitor: allow register hmp commands
>   usb: drop usb_host_dev_is_scsi_storage hook
>   monitor/usb: register 'info usbhost' dynamically
>   usb: build usb-host as module
>   monitor/tcg: move tcg hmp commands to accel/tcg, register them
>     dynamically
> 
> Jose R. Ziviani (1):
>   modules: check if all dependencies can be satisfied
> 
>  scripts/modinfo-collect.py      |  67 +++++++++++
>  scripts/modinfo-generate.py     |  97 ++++++++++++++++
>  include/hw/usb.h                |   7 +-
>  include/monitor/monitor.h       |   3 +
>  include/qemu/module.h           |  74 ++++++++++++
>  accel/accel-common.c            |   2 +-
>  accel/accel-softmmu.c           |   2 +-
>  accel/qtest/qtest.c             |   2 +
>  accel/tcg/hmp.c                 |  29 +++++
>  accel/tcg/tcg-accel-ops.c       |   1 +
>  accel/tcg/tcg-all.c             |   1 +
>  audio/spiceaudio.c              |   2 +
>  block/iscsi-opts.c              |   1 +
>  chardev/baum.c                  |   1 +
>  chardev/spice.c                 |   4 +
>  hw/display/qxl.c                |   4 +
>  hw/display/vhost-user-gpu-pci.c |   1 +
>  hw/display/vhost-user-gpu.c     |   1 +
>  hw/display/vhost-user-vga.c     |   1 +
>  hw/display/virtio-gpu-base.c    |   1 +
>  hw/display/virtio-gpu-gl.c      |   3 +
>  hw/display/virtio-gpu-pci-gl.c  |   3 +
>  hw/display/virtio-gpu-pci.c     |   2 +
>  hw/display/virtio-gpu.c         |   1 +
>  hw/display/virtio-vga-gl.c      |   3 +
>  hw/display/virtio-vga.c         |   2 +
>  hw/ppc/spapr.c                  |   2 +-
>  hw/s390x/virtio-ccw-gpu.c       |   3 +
>  hw/usb/ccid-card-emulated.c     |   1 +
>  hw/usb/ccid-card-passthru.c     |   1 +
>  hw/usb/dev-storage-bot.c        |   1 +
>  hw/usb/dev-storage-classic.c    |   1 +
>  hw/usb/dev-uas.c                |   1 +
>  hw/usb/host-libusb.c            |  38 ++----
>  hw/usb/host-stub.c              |  45 -------
>  hw/usb/redirect.c               |   1 +
>  monitor/hmp.c                   |   7 ++
>  monitor/misc.c                  |  34 +++---
>  softmmu/vl.c                    |  24 ++--
>  stubs/module-opts.c             |   4 -
>  ui/egl-headless.c               |   4 +
>  ui/gtk.c                        |   4 +
>  ui/sdl2.c                       |   4 +
>  ui/spice-app.c                  |   3 +
>  ui/spice-core.c                 |   5 +
>  util/module.c                   | 200 ++++++++++++++++++--------------
>  accel/qtest/meson.build         |   8 +-
>  accel/tcg/meson.build           |   6 +-
>  docs/devel/build-system.rst     |  17 +++
>  docs/devel/index.rst            |   1 +
>  docs/devel/modules.rst          |   5 +
>  docs/devel/qom.rst              |   8 ++
>  hmp-commands-info.hx            |   3 -
>  hw/usb/meson.build              |  10 +-
>  meson.build                     |  82 +++++++++++++
>  util/trace-events               |   4 +
>  56 files changed, 624 insertions(+), 218 deletions(-)
>  create mode 100755 scripts/modinfo-collect.py
>  create mode 100755 scripts/modinfo-generate.py
>  create mode 100644 accel/tcg/hmp.c
>  delete mode 100644 hw/usb/host-stub.c
>  create mode 100644 docs/devel/modules.rst
> 
> -- 
> 2.31.1
> 
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK