Quoting Ville Syrjälä (2019-11-14 10:53:11) > On Wed, Nov 13, 2019 at 05:19:44PM +0000, Chris Wilson wrote: > > Do not leak our internal kernel address for random userspace to abuse. > > Daniel added the support to fbdev to filter out the physical addresses > > being exposed by fbdev, put that to use to protect ourselves. > > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112256 > > Fixes: 5f889b9a61dd ("drm/i915: Disregard drm_mode_config.fb_base") > > References: da6c7707caf3 ("fbdev: Add FBINFO_HIDE_SMEM_START flag") > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > > --- > > drivers/gpu/drm/i915/display/intel_fbdev.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c > > index 3d1061470e76..bff311561597 100644 > > --- a/drivers/gpu/drm/i915/display/intel_fbdev.c > > +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c > > @@ -226,8 +226,8 @@ static int intelfb_create(struct drm_fb_helper *helper, > > goto out_unpin; > > } > > > > - ifbdev->helper.fb = &ifbdev->fb->base; > > - > > + /* don't leak any physical addresses to userspace */ > > + info->flags |= FBINFO_HIDE_SMEM_START; > > Doesn't the fb helper already do this? > > Looks like it tries. Though I have no idea why it does > it in initial_config() instead of fill_fb_info(). I wasn't even sure we took that path. > > info->fbops = &intelfb_ops; > > > > /* setup aperture base/size for vesafb takeover */ > > @@ -247,6 +247,7 @@ static int intelfb_create(struct drm_fb_helper *helper, > > info->fix.smem_start = (unsigned long)info->screen_base; > > Isn't screen_base the virtual address? Why do we put that into > smem_start? I made the mistake of thinking it was only internally used. So I take that as an implicit r-b for the fix and the igt proving that I was dumb... https://patchwork.freedesktop.org/series/69416/ https://patchwork.freedesktop.org/series/69421/ -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
