Re: [PATCH v2 00/10] drm/msm: probe deferral fixes

Johan Hovold
2022-10-21T06:28:23Z

On Tue, Sep 20, 2022 at 11:06:30AM +0200, Johan Hovold wrote:
> On Tue, Sep 13, 2022 at 10:53:10AM +0200, Johan Hovold wrote:
> > The MSM DRM driver is currently broken in multiple ways with respect to
> > probe deferral. Not only does the driver currently fail to probe again
> > after a late deferral, but due to a related use-after-free bug this also
> > triggers NULL-pointer dereferences.
> >
> > These bugs are not new but have become critical with the release of
> > 5.19 where probe is deferred in case the aux-bus EP panel driver has not
> > yet been loaded.
> >
> > The underlying problem is lifetime issues due to careless use of
> > device-managed resources.
>
> Any chance of getting this merged for 6.1?

Is anyone picking these up as fixes for 6.1-rc as we discussed?

Johan

> > Changes in v2
> > - use a custom devres action instead of amending the AUX bus interface
> > (Doug)
> > - split sanity check fixes and cleanups per bridge type (Dmitry)
> > - add another Fixes tag for the missing bridge counter reset (Dmitry)
> >
> >
> > Johan Hovold (10):
> > drm/msm: fix use-after-free on probe deferral
> > drm/msm/dp: fix memory corruption with too many bridges
> > drm/msm/dsi: fix memory corruption with too many bridges
> > drm/msm/hdmi: fix memory corruption with too many bridges
> > drm/msm/dp: fix IRQ lifetime
> > drm/msm/dp: fix aux-bus EP lifetime
> > drm/msm/dp: fix bridge lifetime
> > drm/msm/hdmi: fix IRQ lifetime
> > drm/msm/dp: drop modeset sanity checks
> > drm/msm/dsi: drop modeset sanity checks
> >
> > drivers/gpu/drm/msm/dp/dp_display.c | 26 +++++++++++++++++++-------
> > drivers/gpu/drm/msm/dp/dp_parser.c | 6 +++---
> > drivers/gpu/drm/msm/dp/dp_parser.h | 5 +++--
> > drivers/gpu/drm/msm/dsi/dsi.c | 9 +++++----
> > drivers/gpu/drm/msm/hdmi/hdmi.c | 7 ++++++-
> > drivers/gpu/drm/msm/msm_drv.c | 1 +
> > 6 files changed, 37 insertions(+), 17 deletions(-)