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Unified Diff: content/common/sandbox_linux/sandbox_linux.cc

Issue 114483003: Revert of Linux Sandbox: split the GPU policies to their own file. (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src
Patch Set: Created 7 years ago
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Index: content/common/sandbox_linux/sandbox_linux.cc
diff --git a/content/common/sandbox_linux/sandbox_linux.cc b/content/common/sandbox_linux/sandbox_linux.cc
deleted file mode 100644
index 2aa4f2899d57b7a6ba74a6eea5c80e00bcace50d..0000000000000000000000000000000000000000
--- a/content/common/sandbox_linux/sandbox_linux.cc
+++ /dev/null
@@ -1,299 +0,0 @@
-// 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 <dirent.h>
-#include <fcntl.h>
-#include <sys/resource.h>
-#include <sys/stat.h>
-#include <sys/time.h>
-#include <sys/types.h>
-
-#include <limits>
-
-#include "base/bind.h"
-#include "base/callback_helpers.h"
-#include "base/command_line.h"
-#include "base/logging.h"
-#include "base/memory/singleton.h"
-#include "base/posix/eintr_wrapper.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/time/time.h"
-#include "content/common/sandbox_linux/sandbox_linux.h"
-#include "content/common/sandbox_linux/sandbox_seccomp_bpf_linux.h"
-#include "content/public/common/content_switches.h"
-#include "content/public/common/sandbox_linux.h"
-#include "sandbox/linux/services/credentials.h"
-#include "sandbox/linux/suid/client/setuid_sandbox_client.h"
-
-namespace {
-
-void LogSandboxStarted(const std::string& sandbox_name) {
- const CommandLine& command_line = *CommandLine::ForCurrentProcess();
- const std::string process_type =
- command_line.GetSwitchValueASCII(switches::kProcessType);
- const std::string activated_sandbox =
- "Activated " + sandbox_name + " sandbox for process type: " +
- process_type + ".";
-#if defined(OS_CHROMEOS)
- LOG(WARNING) << activated_sandbox;
-#else
- VLOG(1) << activated_sandbox;
-#endif
-}
-
-bool AddResourceLimit(int resource, rlim_t limit) {
- struct rlimit old_rlimit;
- if (getrlimit(resource, &old_rlimit))
- return false;
- // Make sure we don't raise the existing limit.
- const struct rlimit new_rlimit = {
- std::min(old_rlimit.rlim_cur, limit),
- std::min(old_rlimit.rlim_max, limit)
- };
- int rc = setrlimit(resource, &new_rlimit);
- return rc == 0;
-}
-
-bool IsRunningTSAN() {
-#if defined(THREAD_SANITIZER)
- return true;
-#else
- return false;
-#endif
-}
-
-} // namespace
-
-namespace content {
-
-LinuxSandbox::LinuxSandbox()
- : proc_fd_(-1),
- seccomp_bpf_started_(false),
- pre_initialized_(false),
- seccomp_bpf_supported_(false),
- setuid_sandbox_client_(sandbox::SetuidSandboxClient::Create()) {
- if (setuid_sandbox_client_ == NULL) {
- LOG(FATAL) << "Failed to instantiate the setuid sandbox client.";
- }
-}
-
-LinuxSandbox::~LinuxSandbox() {
-}
-
-LinuxSandbox* LinuxSandbox::GetInstance() {
- LinuxSandbox* instance = Singleton<LinuxSandbox>::get();
- CHECK(instance);
- return instance;
-}
-
-#if defined(ADDRESS_SANITIZER) && defined(OS_LINUX)
-// ASan API call to notify the tool the sandbox is going to be turned on.
-extern "C" void __sanitizer_sandbox_on_notify(void *reserved);
-#endif
-
-void LinuxSandbox::PreinitializeSandbox() {
- CHECK(!pre_initialized_);
- seccomp_bpf_supported_ = false;
-#if defined(ADDRESS_SANITIZER) && defined(OS_LINUX)
- // ASan needs to open some resources before the sandbox is enabled.
- // This should not fork, not launch threads, not open a directory.
- __sanitizer_sandbox_on_notify(/*reserved*/NULL);
-#endif
-
-#if !defined(NDEBUG)
- // Open proc_fd_ only in Debug mode so that forgetting to close it doesn't
- // produce a sandbox escape in Release mode.
- proc_fd_ = open("/proc", O_DIRECTORY | O_RDONLY);
- CHECK_GE(proc_fd_, 0);
-#endif // !defined(NDEBUG)
- // We "pre-warm" the code that detects supports for seccomp BPF.
- if (SandboxSeccompBPF::IsSeccompBPFDesired()) {
- if (!SandboxSeccompBPF::SupportsSandbox()) {
- VLOG(1) << "Lacking support for seccomp-bpf sandbox.";
- } else {
- seccomp_bpf_supported_ = true;
- }
- }
- pre_initialized_ = true;
-}
-
-bool LinuxSandbox::InitializeSandbox() {
- bool seccomp_bpf_started = false;
- LinuxSandbox* linux_sandbox = LinuxSandbox::GetInstance();
- // We need to make absolutely sure that our sandbox is "sealed" before
- // InitializeSandbox does exit.
- base::ScopedClosureRunner sandbox_sealer(
- base::Bind(&LinuxSandbox::SealSandbox, base::Unretained(linux_sandbox)));
- const std::string process_type =
- CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
- switches::kProcessType);
-
- // No matter what, it's always an error to call InitializeSandbox() after
- // threads have been created.
- if (!linux_sandbox->IsSingleThreaded()) {
- std::string error_message = "InitializeSandbox() called with multiple "
- "threads in process " + process_type;
- // TSAN starts a helper thread. So we don't start the sandbox and don't
- // even report an error about it.
- if (IsRunningTSAN())
- return false;
- // The GPU process is allowed to call InitializeSandbox() with threads for
- // now, because it loads third party libraries.
- if (process_type != switches::kGpuProcess)
- CHECK(false) << error_message;
- LOG(ERROR) << error_message;
- return false;
- }
-
- DCHECK(!linux_sandbox->HasOpenDirectories()) <<
- "InitializeSandbox() called after unexpected directories have been " <<
- "opened. This breaks the security of the setuid sandbox.";
-
- // Attempt to limit the future size of the address space of the process.
- linux_sandbox->LimitAddressSpace(process_type);
-
- // First, try to enable seccomp-bpf.
- seccomp_bpf_started = linux_sandbox->StartSeccompBPF(process_type);
-
- return seccomp_bpf_started;
-}
-
-int LinuxSandbox::GetStatus() const {
- CHECK(pre_initialized_);
- int sandbox_flags = 0;
- if (setuid_sandbox_client_->IsSandboxed()) {
- sandbox_flags |= kSandboxLinuxSUID;
- if (setuid_sandbox_client_->IsInNewPIDNamespace())
- sandbox_flags |= kSandboxLinuxPIDNS;
- if (setuid_sandbox_client_->IsInNewNETNamespace())
- sandbox_flags |= kSandboxLinuxNetNS;
- }
-
- if (seccomp_bpf_supported() &&
- SandboxSeccompBPF::ShouldEnableSeccompBPF(switches::kRendererProcess)) {
- // We report whether the sandbox will be activated when renderers go
- // through sandbox initialization.
- sandbox_flags |= kSandboxLinuxSeccompBPF;
- }
-
- return sandbox_flags;
-}
-
-// Threads are counted via /proc/self/task. This is a little hairy because of
-// PID namespaces and existing sandboxes, so "self" must really be used instead
-// of using the pid.
-bool LinuxSandbox::IsSingleThreaded() const {
- struct stat task_stat;
- int fstat_ret;
- if (proc_fd_ >= 0) {
- // If a handle to /proc is available, use it. This allows to bypass file
- // system restrictions.
- fstat_ret = fstatat(proc_fd_, "self/task/", &task_stat, 0);
- } else {
- // Otherwise, make an attempt to access the file system directly.
- fstat_ret = fstatat(AT_FDCWD, "/proc/self/task/", &task_stat, 0);
- }
- // In Debug mode, it's mandatory to be able to count threads to catch bugs.
-#if !defined(NDEBUG)
- // Using DCHECK here would be incorrect. DCHECK can be enabled in non
- // official release mode.
- CHECK_EQ(0, fstat_ret) << "Could not count threads, the sandbox was not "
- << "pre-initialized properly.";
-#endif // !defined(NDEBUG)
- if (fstat_ret) {
- // Pretend to be monothreaded if it can't be determined (for instance the
- // setuid sandbox is already engaged but no proc_fd_ is available).
- return true;
- }
-
- // At least "..", "." and the current thread should be present.
- CHECK_LE(3UL, task_stat.st_nlink);
- // Counting threads via /proc/self/task could be racy. For the purpose of
- // determining if the current proces is monothreaded it works: if at any
- // time it becomes monothreaded, it'll stay so.
- return task_stat.st_nlink == 3;
-}
-
-bool LinuxSandbox::seccomp_bpf_started() const {
- return seccomp_bpf_started_;
-}
-
-sandbox::SetuidSandboxClient*
- LinuxSandbox::setuid_sandbox_client() const {
- return setuid_sandbox_client_.get();
-}
-
-// For seccomp-bpf, we use the SandboxSeccompBPF class.
-bool LinuxSandbox::StartSeccompBPF(const std::string& process_type) {
- CHECK(!seccomp_bpf_started_);
- if (!pre_initialized_)
- PreinitializeSandbox();
- if (seccomp_bpf_supported())
- seccomp_bpf_started_ = SandboxSeccompBPF::StartSandbox(process_type);
-
- if (seccomp_bpf_started_)
- LogSandboxStarted("seccomp-bpf");
-
- return seccomp_bpf_started_;
-}
-
-bool LinuxSandbox::seccomp_bpf_supported() const {
- CHECK(pre_initialized_);
- return seccomp_bpf_supported_;
-}
-
-bool LinuxSandbox::LimitAddressSpace(const std::string& process_type) {
- (void) process_type;
-#if !defined(ADDRESS_SANITIZER)
- CommandLine* command_line = CommandLine::ForCurrentProcess();
- if (command_line->HasSwitch(switches::kNoSandbox)) {
- return false;
- }
-
- // Limit the address space to 4GB.
- // This is in the hope of making some kernel exploits more complex and less
- // reliable. It also limits sprays a little on 64-bit.
- rlim_t address_space_limit = std::numeric_limits<uint32_t>::max();
-#if defined(__LP64__)
- // On 64 bits, V8 and possibly others will reserve massive memory ranges and
- // rely on on-demand paging for allocation. Unfortunately, even
- // MADV_DONTNEED ranges count towards RLIMIT_AS so this is not an option.
- // See crbug.com/169327 for a discussion.
- // On the GPU process, irrespective of V8, we can exhaust a 4GB address space
- // under normal usage, see crbug.com/271119
- // For now, increase limit to 16GB for renderer and worker and gpu processes
- // to accomodate.
- if (process_type == switches::kRendererProcess ||
- process_type == switches::kWorkerProcess ||
- process_type == switches::kGpuProcess) {
- address_space_limit = 1L << 34;
- }
-#endif // defined(__LP64__)
-
- // On all platforms, add a limit to the brk() heap that would prevent
- // allocations that can't be index by an int.
- const rlim_t kNewDataSegmentMaxSize = std::numeric_limits<int>::max();
-
- bool limited_as = AddResourceLimit(RLIMIT_AS, address_space_limit);
- bool limited_data = AddResourceLimit(RLIMIT_DATA, kNewDataSegmentMaxSize);
- return limited_as && limited_data;
-#else
- return false;
-#endif // !defined(ADDRESS_SANITIZER)
-}
-
-bool LinuxSandbox::HasOpenDirectories() {
- return sandbox::Credentials().HasOpenDirectory(proc_fd_);
-}
-
-void LinuxSandbox::SealSandbox() {
- if (proc_fd_ >= 0) {
- int ret = IGNORE_EINTR(close(proc_fd_));
- CHECK_EQ(0, ret);
- proc_fd_ = -1;
- }
-}
-
-} // namespace content
-
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