Linux sandbox: always restrict clone() in baseline policy.

content/common/sandbox_linux/bpf_renderer_policy_linux.cc

 // Copyright 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 "content/common/sandbox_linux/bpf_renderer_policy_linux.h"
 
 #include <errno.h>
 
 #include "base/basictypes.h"
 #include "build/build_config.h"
 #include "content/common/sandbox_linux/sandbox_linux.h"
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.h"
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_sets.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf_policy.h"
 #include "sandbox/linux/services/linux_syscalls.h"
 
 using sandbox::SyscallSets;
 
 namespace content {
 
 RendererProcessPolicy::RendererProcessPolicy() {}
 RendererProcessPolicy::~RendererProcessPolicy() {}
 
 ErrorCode RendererProcessPolicy::EvaluateSyscall(SandboxBPF* sandbox,
                                                  int sysno) const {
   switch (sysno) {
-    case __NR_clone:
-      return sandbox::RestrictCloneToThreadsAndEPERMFork(sandbox);
     case __NR_ioctl:
       return sandbox::RestrictIoctl(sandbox);
     case __NR_prctl:
       return sandbox::RestrictPrctl(sandbox);
     // Allow the system calls below.
     // The baseline policy allows __NR_clock_gettime. Allow
     // clock_getres() for V8. crbug.com/329053.
     case __NR_clock_getres:
     case __NR_fdatasync:
     case __NR_fsync:
@@ skipping 20 matching lines @@
       return ErrorCode(ErrorCode::ERR_ALLOWED);
     case __NR_prlimit64:
       return ErrorCode(EPERM);  // See crbug.com/160157.
     default:
       // Default on the content baseline policy.
       return SandboxBPFBasePolicy::EvaluateSyscall(sandbox, sysno);
   }
 }
 
 }  // namespace content