drm/vmwgfx: check master authentication in surface_ref ioctls

With later commit we'll rework DRM authentication handling. Namely
DRM_AUTH will not be a requirement for DRM_RENDER_ALLOW ioctls.

Since vmwgfx does isolation for primary clients in different master
realms, the DRM_AUTH can be dropped.

The only place where authentication matters, is surface_reference ioctls
whenever a legacy (non-prime) handle is used. For those ioctls we call
vmw_surface_handle_reference(), where we explicitly check if the client
is both a) master and b) unauthenticated - bailing out as result.

Otherwise the usual isolation path kicks in and we're all good.

v2: Reword commit message, since the isolation work has landed.

Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index 590bde99394699cc680f2d2a38da4fbc856e7ce8..3ce630aa4fde5099bc6ed4678d4c3c2c433edc2f 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -961,6 +961,13 @@ vmw_surface_handle_reference(struct vmw_private *dev_priv,
                user_srf = container_of(base, struct vmw_user_surface,
                                        prime.base);
 
+               /* Error out if we are unauthenticated primary */
+               if (drm_is_primary_client(file_priv) &&
+                   !file_priv->authenticated) {
+                       ret = -EACCES;
+                       goto out_bad_resource;
+               }
+
                /*
                 * Make sure the surface creator has the same
                 * authenticating master, or is already registered with us.