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(). > 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? > info->fix.smem_len = info->screen_size; > > + ifbdev->helper.fb = &ifbdev->fb->base; > drm_fb_helper_fill_info(info, &ifbdev->helper, sizes); > > /* If the object is shmemfs backed, it will have given us zeroed pages. > -- > 2.24.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
