Linux sandbox: restrict prctl in the baseline.

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

 // Copyright 2014 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/baseline_policy.h"
 
 #include <errno.h>
 #include <linux/futex.h>
 #include <sched.h>
 #include <signal.h>
 #include <string.h>
+#include <sys/prctl.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include "base/files/scoped_file.h"
 #include "base/macros.h"
@@ skipping 233 matching lines @@
 
 BPF_DEATH_TEST_C(BaselinePolicy,
                  FutexWithRequeuePriorityInheritencePrivate,
                  DEATH_MESSAGE(GetFutexErrorMessageContentForTests()),
                  BaselinePolicy) {
   syscall(__NR_futex, NULL, FUTEX_CMP_REQUEUE_PI_PRIVATE, 0, NULL, NULL, 0);
   _exit(1);
 }
 #endif  // !defined(OS_ANDROID)
 
+BPF_TEST_C(BaselinePolicy, PrctlDumpable, BaselinePolicy) {
+  const int is_dumpable = prctl(PR_GET_DUMPABLE, 0, 0, 0, 0);
+  BPF_ASSERT(is_dumpable == 1 || is_dumpable == 0);
+  const int prctl_ret = prctl(PR_SET_DUMPABLE, is_dumpable, 0, 0, 0, 0);
+  BPF_ASSERT_EQ(0, prctl_ret);
+}
+
+// Workaround incomplete Android headers.
+#if !defined(PR_CAPBSET_READ)
+#define PR_CAPBSET_READ 23
+#endif
+
+BPF_DEATH_TEST_C(BaselinePolicy,
+                 PrctlSigsys,
+                 DEATH_MESSAGE(GetPrctlErrorMessageContentForTests()),
+                 BaselinePolicy) {
+  prctl(PR_CAPBSET_READ, 0, 0, 0, 0);
+  _exit(1);
+}
+
 }  // namespace
 
 }  // namespace sandbox