I comfirm that setuid(0) fixes my issue! Thank you for your advise. I made a small patch of the workaround for nvidia-modprobe. Please check the attached file.
The configuration in /etc/modprobe.d/nvidia.conf requires to fork /bin/sh with root privilege because it contains some shell commands. So, I think this issue affects to most of users. Regards, Hiromasa YOSHIMOTO
--- nvidia-modprobe-384.111.orig/modprobe-utils/nvidia-modprobe-utils.c +++ nvidia-modprobe-384.111/modprobe-utils/nvidia-modprobe-utils.c @@ -374,6 +374,10 @@ static int modprobe_helper(const int pri */ silence_current_process(); + /* Workaround for debian's /etc/modprobe.d/nvidia.conf configuration. + * See Bug#888952 for details */ + setuid(0); + execle(modprobe_path, "modprobe", module_name, NULL, envp);