Linux sandbox: Disallow get_robust_list and set_robust_list.

sandbox/linux/seccomp-bpf-helpers/syscall_sets.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_sets.h"
 
 #include "build/build_config.h"
 #include "sandbox/linux/services/linux_syscalls.h"
 
 namespace sandbox {
@@ skipping 384 matching lines @@
     default:
       return false;
   }
 }
 
 // It's difficult to restrict those, but there is attack surface here.
 bool SyscallSets::IsAllowedFutex(int sysno) {
   switch (sysno) {
     case __NR_get_robust_list:
     case __NR_set_robust_list:
-      return true;
     case __NR_futex:
     default:
       return false;
   }
 }
 
 bool SyscallSets::IsAllowedEpoll(int sysno) {
   switch (sysno) {
 #if !defined(__aarch64__)
     case __NR_epoll_create:
@@ skipping 636 matching lines @@
   switch (sysno) {
     case __NR_sysmips:
     case __NR_unused150:
       return true;
     default:
       return false;
   }
 }
 #endif  // defined(__mips__)
 }  // namespace sandbox.