If using legacy (non-prime) surface sharing, only allow surfaces to be shared between clients with the same master. This will block malicious clients from peeking at contents at surfaces from other (possibly vt-switched) masters.
v2: s/legacy_client/primary_client/
Signed-off-by: Thomas Hellstrom thellstrom@vmware.com Reviewed-by: Brian Paul brianp@vmware.com --- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index d50cd76..4ecdbf3 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -36,11 +36,13 @@ * @base: The TTM base object handling user-space visibility. * @srf: The surface metadata. * @size: TTM accounting size for the surface. + * @master: master of the creating client. Used for security check. */ struct vmw_user_surface { struct ttm_prime_object prime; struct vmw_surface srf; uint32_t size; + struct drm_master *master; };
/** @@ -624,6 +626,8 @@ static void vmw_user_surface_free(struct vmw_resource *res) struct vmw_private *dev_priv = srf->res.dev_priv; uint32_t size = user_srf->size;
+ if (user_srf->master) + drm_master_put(&user_srf->master); kfree(srf->offsets); kfree(srf->sizes); kfree(srf->snooper.image); @@ -819,6 +823,8 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
user_srf->prime.base.shareable = false; user_srf->prime.base.tfile = NULL; + if (drm_is_primary_client(file_priv)) + user_srf->master = drm_master_get(file_priv->master);
/** * From this point, the generic resource management functions @@ -885,6 +891,7 @@ vmw_surface_handle_reference(struct vmw_private *dev_priv, struct ttm_base_object **base_p) { struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile; + struct vmw_user_surface *user_srf; uint32_t handle; struct ttm_base_object *base; int ret; @@ -915,6 +922,21 @@ vmw_surface_handle_reference(struct vmw_private *dev_priv, }
if (handle_type != DRM_VMW_HANDLE_PRIME) { + user_srf = container_of(base, struct vmw_user_surface, + prime.base); + + /* + * Make sure the surface creator has the same + * authenticating master. + */ + if (drm_is_primary_client(file_priv) && + user_srf->master != file_priv->master) { + DRM_ERROR("Trying to reference surface outside of" + " master domain.\n"); + ret = -EACCES; + goto out_bad_resource; + } + ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL); if (unlikely(ret != 0)) { DRM_ERROR("Could not add a reference to a surface.\n"); @@ -1273,6 +1295,8 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, void *data,
user_srf->prime.base.shareable = false; user_srf->prime.base.tfile = NULL; + if (drm_is_primary_client(file_priv)) + user_srf->master = drm_master_get(file_priv->master);
/** * From this point, the generic resource management functions