4.15-stable review patch. If anyone has any objections, please let me know.
------------------ From: Keith Packard <[email protected]> commit 761e05a702f5d537ffcca1ba933f9f0a968aa022 upstream. Don't let a lessee control what the current DRM master is set to; that's the job of the "real" master. Otherwise, the lessee would disable all access to master operations for the owner and all lessees under it. This matches the same check made in the SET_MASTER ioctl. Signed-off-by: Keith Packard <[email protected]> Fixes: 2ed077e467ee ("drm: Add drm_object lease infrastructure [v5]") Cc: <[email protected]> # v4.15+ Signed-off-by: Daniel Vetter <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/drm_auth.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -230,6 +230,12 @@ int drm_dropmaster_ioctl(struct drm_devi if (!dev->master) goto out_unlock; + if (file_priv->master->lessor != NULL) { + DRM_DEBUG_LEASE("Attempt to drop lessee %d as master\n", file_priv->master->lessee_id); + ret = -EINVAL; + goto out_unlock; + } + ret = 0; drm_drop_master(dev, file_priv); out_unlock:
