Update from chromium 62675d9fb31fb8cedc40f68e78e8445a74f362e7

sandbox/linux/services/broker_process_unittest.cc

+// Copyright (c) 2012 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/services/broker_process.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_file.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/posix/unix_domain_socket_linux.h"
+#include "sandbox/linux/tests/scoped_temporary_file.h"
+#include "sandbox/linux/tests/test_utils.h"
+#include "sandbox/linux/tests/unit_tests.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace sandbox {
+
+class BrokerProcessTestHelper {
+ public:
+  static int get_ipc_socketpair(const BrokerProcess* broker) {
+    return broker->ipc_socketpair_;
+  }
+};
+
+namespace {
+
+bool NoOpCallback() { return true; }
+
+}  // namespace
+
+TEST(BrokerProcess, CreateAndDestroy) {
+  std::vector<std::string> read_whitelist;
+  read_whitelist.push_back("/proc/cpuinfo");
+
+  scoped_ptr<BrokerProcess> open_broker(
+      new BrokerProcess(EPERM, read_whitelist, std::vector<std::string>()));
+  ASSERT_TRUE(open_broker->Init(base::Bind(&NoOpCallback)));
+
+  ASSERT_TRUE(TestUtils::CurrentProcessHasChildren());
+  // Destroy the broker and check it has exited properly.
+  open_broker.reset();
+  ASSERT_FALSE(TestUtils::CurrentProcessHasChildren());
+}
+
+TEST(BrokerProcess, TestOpenAccessNull) {
+  const std::vector<std::string> empty;
+  BrokerProcess open_broker(EPERM, empty, empty);
+  ASSERT_TRUE(open_broker.Init(base::Bind(&NoOpCallback)));
+
+  int fd = open_broker.Open(NULL, O_RDONLY);
+  ASSERT_EQ(fd, -EFAULT);
+
+  int ret = open_broker.Access(NULL, F_OK);
+  ASSERT_EQ(ret, -EFAULT);
+}
+
+void TestOpenFilePerms(bool fast_check_in_client, int denied_errno) {
+  const char kR_WhiteListed[] = "/proc/DOESNOTEXIST1";
+  // We can't debug the init process, and shouldn't be able to access
+  // its auxv file.
+  const char kR_WhiteListedButDenied[] = "/proc/1/auxv";
+  const char kW_WhiteListed[] = "/proc/DOESNOTEXIST2";
+  const char kRW_WhiteListed[] = "/proc/DOESNOTEXIST3";
+  const char k_NotWhitelisted[] = "/proc/DOESNOTEXIST4";
+
+  std::vector<std::string> read_whitelist;
+  read_whitelist.push_back(kR_WhiteListed);
+  read_whitelist.push_back(kR_WhiteListedButDenied);
+  read_whitelist.push_back(kRW_WhiteListed);
+
+  std::vector<std::string> write_whitelist;
+  write_whitelist.push_back(kW_WhiteListed);
+  write_whitelist.push_back(kRW_WhiteListed);
+
+  BrokerProcess open_broker(denied_errno,
+                            read_whitelist,
+                            write_whitelist,
+                            fast_check_in_client);
+  ASSERT_TRUE(open_broker.Init(base::Bind(&NoOpCallback)));
+
+  int fd = -1;
+  fd = open_broker.Open(kR_WhiteListed, O_RDONLY);
+  ASSERT_EQ(fd, -ENOENT);
+  fd = open_broker.Open(kR_WhiteListed, O_WRONLY);
+  ASSERT_EQ(fd, -denied_errno);
+  fd = open_broker.Open(kR_WhiteListed, O_RDWR);
+  ASSERT_EQ(fd, -denied_errno);
+  int ret = -1;
+  ret = open_broker.Access(kR_WhiteListed, F_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kR_WhiteListed, R_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kR_WhiteListed, W_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(kR_WhiteListed, R_OK | W_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(kR_WhiteListed, X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(kR_WhiteListed, R_OK | X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+
+  // Android sometimes runs tests as root.
+  // This part of the test requires a process that doesn't have
+  // CAP_DAC_OVERRIDE. We check against a root euid as a proxy for that.
+  if (geteuid()) {
+    fd = open_broker.Open(kR_WhiteListedButDenied, O_RDONLY);
+    // The broker process will allow this, but the normal permission system
+    // won't.
+    ASSERT_EQ(fd, -EACCES);
+    fd = open_broker.Open(kR_WhiteListedButDenied, O_WRONLY);
+    ASSERT_EQ(fd, -denied_errno);
+    fd = open_broker.Open(kR_WhiteListedButDenied, O_RDWR);
+    ASSERT_EQ(fd, -denied_errno);
+    ret = open_broker.Access(kR_WhiteListedButDenied, F_OK);
+    // The normal permission system will let us check that the file exists.
+    ASSERT_EQ(ret, 0);
+    ret = open_broker.Access(kR_WhiteListedButDenied, R_OK);
+    ASSERT_EQ(ret, -EACCES);
+    ret = open_broker.Access(kR_WhiteListedButDenied, W_OK);
+    ASSERT_EQ(ret, -denied_errno);
+    ret = open_broker.Access(kR_WhiteListedButDenied, R_OK | W_OK);
+    ASSERT_EQ(ret, -denied_errno);
+    ret = open_broker.Access(kR_WhiteListedButDenied, X_OK);
+    ASSERT_EQ(ret, -denied_errno);
+    ret = open_broker.Access(kR_WhiteListedButDenied, R_OK | X_OK);
+    ASSERT_EQ(ret, -denied_errno);
+  }
+
+  fd = open_broker.Open(kW_WhiteListed, O_RDONLY);
+  ASSERT_EQ(fd, -denied_errno);
+  fd = open_broker.Open(kW_WhiteListed, O_WRONLY);
+  ASSERT_EQ(fd, -ENOENT);
+  fd = open_broker.Open(kW_WhiteListed, O_RDWR);
+  ASSERT_EQ(fd, -denied_errno);
+  ret = open_broker.Access(kW_WhiteListed, F_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kW_WhiteListed, R_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(kW_WhiteListed, W_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kW_WhiteListed, R_OK | W_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(kW_WhiteListed, X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(kW_WhiteListed, R_OK | X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+
+  fd = open_broker.Open(kRW_WhiteListed, O_RDONLY);
+  ASSERT_EQ(fd, -ENOENT);
+  fd = open_broker.Open(kRW_WhiteListed, O_WRONLY);
+  ASSERT_EQ(fd, -ENOENT);
+  fd = open_broker.Open(kRW_WhiteListed, O_RDWR);
+  ASSERT_EQ(fd, -ENOENT);
+  ret = open_broker.Access(kRW_WhiteListed, F_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kRW_WhiteListed, R_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kRW_WhiteListed, W_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kRW_WhiteListed, R_OK | W_OK);
+  ASSERT_EQ(ret, -ENOENT);
+  ret = open_broker.Access(kRW_WhiteListed, X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(kRW_WhiteListed, R_OK | X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+
+  fd = open_broker.Open(k_NotWhitelisted, O_RDONLY);
+  ASSERT_EQ(fd, -denied_errno);
+  fd = open_broker.Open(k_NotWhitelisted, O_WRONLY);
+  ASSERT_EQ(fd, -denied_errno);
+  fd = open_broker.Open(k_NotWhitelisted, O_RDWR);
+  ASSERT_EQ(fd, -denied_errno);
+  ret = open_broker.Access(k_NotWhitelisted, F_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(k_NotWhitelisted, R_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(k_NotWhitelisted, W_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(k_NotWhitelisted, R_OK | W_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(k_NotWhitelisted, X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+  ret = open_broker.Access(k_NotWhitelisted, R_OK | X_OK);
+  ASSERT_EQ(ret, -denied_errno);
+
+  // We have some extra sanity check for clearly wrong values.
+  fd = open_broker.Open(kRW_WhiteListed, O_RDONLY | O_WRONLY | O_RDWR);
+  ASSERT_EQ(fd, -denied_errno);
+
+  // It makes no sense to allow O_CREAT in a 2-parameters open. Ensure this
+  // is denied.
+  fd = open_broker.Open(kRW_WhiteListed, O_RDWR | O_CREAT);
+  ASSERT_EQ(fd, -denied_errno);
+}
+
+// Run the same thing twice. The second time, we make sure that no security
+// check is performed on the client.
+TEST(BrokerProcess, OpenFilePermsWithClientCheck) {
+  TestOpenFilePerms(true /* fast_check_in_client */, EPERM);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+TEST(BrokerProcess, OpenOpenFilePermsNoClientCheck) {
+  TestOpenFilePerms(false /* fast_check_in_client */, EPERM);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+// Run the same twice again, but with ENOENT instead of EPERM.
+TEST(BrokerProcess, OpenFilePermsWithClientCheckNoEnt) {
+  TestOpenFilePerms(true /* fast_check_in_client */, ENOENT);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+TEST(BrokerProcess, OpenOpenFilePermsNoClientCheckNoEnt) {
+  TestOpenFilePerms(false /* fast_check_in_client */, ENOENT);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+void TestOpenCpuinfo(bool fast_check_in_client) {
+  const char kFileCpuInfo[] = "/proc/cpuinfo";
+  std::vector<std::string> read_whitelist;
+  read_whitelist.push_back(kFileCpuInfo);
+
+  scoped_ptr<BrokerProcess> open_broker(new BrokerProcess(
+      EPERM, read_whitelist, std::vector<std::string>(), fast_check_in_client));
+  ASSERT_TRUE(open_broker->Init(base::Bind(&NoOpCallback)));
+
+  int fd = -1;
+  fd = open_broker->Open(kFileCpuInfo, O_RDWR);
+  base::ScopedFD fd_closer(fd);
+  ASSERT_EQ(fd, -EPERM);
+
+  // Check we can read /proc/cpuinfo.
+  int can_access = open_broker->Access(kFileCpuInfo, R_OK);
+  ASSERT_EQ(can_access, 0);
+  can_access = open_broker->Access(kFileCpuInfo, W_OK);
+  ASSERT_EQ(can_access, -EPERM);
+  // Check we can not write /proc/cpuinfo.
+
+  // Open cpuinfo via the broker.
+  int cpuinfo_fd = open_broker->Open(kFileCpuInfo, O_RDONLY);
+  base::ScopedFD cpuinfo_fd_closer(cpuinfo_fd);
+  ASSERT_GE(cpuinfo_fd, 0);
+  char buf[3];
+  memset(buf, 0, sizeof(buf));
+  int read_len1 = read(cpuinfo_fd, buf, sizeof(buf));
+  ASSERT_GT(read_len1, 0);
+
+  // Open cpuinfo directly.
+  int cpuinfo_fd2 = open(kFileCpuInfo, O_RDONLY);
+  base::ScopedFD cpuinfo_fd2_closer(cpuinfo_fd2);
+  ASSERT_GE(cpuinfo_fd2, 0);
+  char buf2[3];
+  memset(buf2, 1, sizeof(buf2));
+  int read_len2 = read(cpuinfo_fd2, buf2, sizeof(buf2));
+  ASSERT_GT(read_len1, 0);
+
+  // The following is not guaranteed true, but will be in practice.
+  ASSERT_EQ(read_len1, read_len2);
+  // Compare the cpuinfo as returned by the broker with the one we opened
+  // ourselves.
+  ASSERT_EQ(memcmp(buf, buf2, read_len1), 0);
+
+  ASSERT_TRUE(TestUtils::CurrentProcessHasChildren());
+  open_broker.reset();
+  ASSERT_FALSE(TestUtils::CurrentProcessHasChildren());
+}
+
+// Run the same thing twice. The second time, we make sure that no security
+// check is performed on the client.
+TEST(BrokerProcess, OpenCpuinfoWithClientCheck) {
+  TestOpenCpuinfo(true /* fast_check_in_client */);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+TEST(BrokerProcess, OpenCpuinfoNoClientCheck) {
+  TestOpenCpuinfo(false /* fast_check_in_client */);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+TEST(BrokerProcess, OpenFileRW) {
+  ScopedTemporaryFile tempfile;
+  const char* tempfile_name = tempfile.full_file_name();
+
+  std::vector<std::string> whitelist;
+  whitelist.push_back(tempfile_name);
+
+  BrokerProcess open_broker(EPERM, whitelist, whitelist);
+  ASSERT_TRUE(open_broker.Init(base::Bind(&NoOpCallback)));
+
+  // Check we can access that file with read or write.
+  int can_access = open_broker.Access(tempfile_name, R_OK | W_OK);
+  ASSERT_EQ(can_access, 0);
+
+  int tempfile2 = -1;
+  tempfile2 = open_broker.Open(tempfile_name, O_RDWR);
+  ASSERT_GE(tempfile2, 0);
+
+  // Write to the descriptor opened by the broker.
+  char test_text[] = "TESTTESTTEST";
+  ssize_t len = write(tempfile2, test_text, sizeof(test_text));
+  ASSERT_EQ(len, static_cast<ssize_t>(sizeof(test_text)));
+
+  // Read back from the original file descriptor what we wrote through
+  // the descriptor provided by the broker.
+  char buf[1024];
+  len = read(tempfile.fd(), buf, sizeof(buf));
+
+  ASSERT_EQ(len, static_cast<ssize_t>(sizeof(test_text)));
+  ASSERT_EQ(memcmp(test_text, buf, sizeof(test_text)), 0);
+
+  ASSERT_EQ(close(tempfile2), 0);
+}
+
+// SANDBOX_TEST because the process could die with a SIGPIPE
+// and we want this to happen in a subprocess.
+SANDBOX_TEST(BrokerProcess, BrokerDied) {
+  std::vector<std::string> read_whitelist;
+  read_whitelist.push_back("/proc/cpuinfo");
+
+  BrokerProcess open_broker(EPERM,
+                            read_whitelist,
+                            std::vector<std::string>(),
+                            true /* fast_check_in_client */,
+                            true /* quiet_failures_for_tests */);
+  SANDBOX_ASSERT(open_broker.Init(base::Bind(&NoOpCallback)));
+  const pid_t broker_pid = open_broker.broker_pid();
+  SANDBOX_ASSERT(kill(broker_pid, SIGKILL) == 0);
+
+  // Now we check that the broker has been signaled, but do not reap it.
+  siginfo_t process_info;
+  SANDBOX_ASSERT(HANDLE_EINTR(waitid(
+                     P_PID, broker_pid, &process_info, WEXITED | WNOWAIT)) ==
+                 0);
+  SANDBOX_ASSERT(broker_pid == process_info.si_pid);
+  SANDBOX_ASSERT(CLD_KILLED == process_info.si_code);
+  SANDBOX_ASSERT(SIGKILL == process_info.si_status);
+
+  // Check that doing Open with a dead broker won't SIGPIPE us.
+  SANDBOX_ASSERT(open_broker.Open("/proc/cpuinfo", O_RDONLY) == -ENOMEM);
+  SANDBOX_ASSERT(open_broker.Access("/proc/cpuinfo", O_RDONLY) == -ENOMEM);
+}
+
+void TestOpenComplexFlags(bool fast_check_in_client) {
+  const char kCpuInfo[] = "/proc/cpuinfo";
+  std::vector<std::string> whitelist;
+  whitelist.push_back(kCpuInfo);
+
+  BrokerProcess open_broker(EPERM,
+                            whitelist,
+                            whitelist,
+                            fast_check_in_client);
+  ASSERT_TRUE(open_broker.Init(base::Bind(&NoOpCallback)));
+  // Test that we do the right thing for O_CLOEXEC and O_NONBLOCK.
+  int fd = -1;
+  int ret = 0;
+  fd = open_broker.Open(kCpuInfo, O_RDONLY);
+  ASSERT_GE(fd, 0);
+  ret = fcntl(fd, F_GETFL);
+  ASSERT_NE(-1, ret);
+  // The descriptor shouldn't have the O_CLOEXEC attribute, nor O_NONBLOCK.
+  ASSERT_EQ(0, ret & (O_CLOEXEC | O_NONBLOCK));
+  ASSERT_EQ(0, close(fd));
+
+  fd = open_broker.Open(kCpuInfo, O_RDONLY | O_CLOEXEC);
+  ASSERT_GE(fd, 0);
+  ret = fcntl(fd, F_GETFD);
+  ASSERT_NE(-1, ret);
+  // Important: use F_GETFD, not F_GETFL. The O_CLOEXEC flag in F_GETFL
+  // is actually not used by the kernel.
+  ASSERT_TRUE(FD_CLOEXEC & ret);
+  ASSERT_EQ(0, close(fd));
+
+  fd = open_broker.Open(kCpuInfo, O_RDONLY | O_NONBLOCK);
+  ASSERT_GE(fd, 0);
+  ret = fcntl(fd, F_GETFL);
+  ASSERT_NE(-1, ret);
+  ASSERT_TRUE(O_NONBLOCK & ret);
+  ASSERT_EQ(0, close(fd));
+}
+
+TEST(BrokerProcess, OpenComplexFlagsWithClientCheck) {
+  TestOpenComplexFlags(true /* fast_check_in_client */);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+TEST(BrokerProcess, OpenComplexFlagsNoClientCheck) {
+  TestOpenComplexFlags(false /* fast_check_in_client */);
+  // Don't do anything here, so that ASSERT works in the subfunction as
+  // expected.
+}
+
+// We need to allow noise because the broker will log when it receives our
+// bogus IPCs.
+SANDBOX_TEST_ALLOW_NOISE(BrokerProcess, RecvMsgDescriptorLeak) {
+  // Android creates a socket on first use of the LOG call.
+  // We need to ensure this socket is open before we
+  // begin the test.
+  LOG(INFO) << "Ensure Android LOG socket is allocated";
+
+  // Find the four lowest available file descriptors.
+  int available_fds[4];
+  SANDBOX_ASSERT(0 == pipe(available_fds));
+  SANDBOX_ASSERT(0 == pipe(available_fds + 2));
+
+  // Save one FD to send to the broker later, and close the others.
+  base::ScopedFD message_fd(available_fds[0]);
+  for (size_t i = 1; i < arraysize(available_fds); i++) {
+    SANDBOX_ASSERT(0 == IGNORE_EINTR(close(available_fds[i])));
+  }
+
+  // Lower our file descriptor limit to just allow three more file descriptors
+  // to be allocated.  (N.B., RLIMIT_NOFILE doesn't limit the number of file
+  // descriptors a process can have: it only limits the highest value that can
+  // be assigned to newly-created descriptors allocated by the process.)
+  const rlim_t fd_limit =
+      1 + *std::max_element(available_fds,
+                            available_fds + arraysize(available_fds));
+
+  // Valgrind doesn't allow changing the hard descriptor limit, so we only
+  // change the soft descriptor limit here.
+  struct rlimit rlim;
+  SANDBOX_ASSERT(0 == getrlimit(RLIMIT_NOFILE, &rlim));
+  SANDBOX_ASSERT(fd_limit <= rlim.rlim_cur);
+  rlim.rlim_cur = fd_limit;
+  SANDBOX_ASSERT(0 == setrlimit(RLIMIT_NOFILE, &rlim));
+
+  static const char kCpuInfo[] = "/proc/cpuinfo";
+  std::vector<std::string> read_whitelist;
+  read_whitelist.push_back(kCpuInfo);
+
+  BrokerProcess open_broker(EPERM, read_whitelist, std::vector<std::string>());
+  SANDBOX_ASSERT(open_broker.Init(base::Bind(&NoOpCallback)));
+
+  const int ipc_fd = BrokerProcessTestHelper::get_ipc_socketpair(&open_broker);
+  SANDBOX_ASSERT(ipc_fd >= 0);
+
+  static const char kBogus[] = "not a pickle";
+  std::vector<int> fds;
+  fds.push_back(message_fd.get());
+
+  // The broker process should only have a couple spare file descriptors
+  // available, but for good measure we send it fd_limit bogus IPCs anyway.
+  for (rlim_t i = 0; i < fd_limit; ++i) {
+    SANDBOX_ASSERT(
+        UnixDomainSocket::SendMsg(ipc_fd, kBogus, sizeof(kBogus), fds));
+  }
+
+  const int fd = open_broker.Open(kCpuInfo, O_RDONLY);
+  SANDBOX_ASSERT(fd >= 0);
+  SANDBOX_ASSERT(0 == IGNORE_EINTR(close(fd)));
+}
+
+}  // namespace sandbox