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firefox/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp
Daniel Baumann 5e9a113729
Adding upstream version 140.0. 
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-25 09:37:52 +02:00

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "SandboxBrokerPolicyFactory.h"
#include "SandboxInfo.h"
#include "SandboxLogging.h"
#include "mozilla/Array.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/Omnijar.h"
#include "mozilla/Preferences.h"
#include "mozilla/SandboxLaunch.h"
#include "mozilla/SandboxSettings.h"
#include "mozilla/StaticPrefs_security.h"
#include "mozilla/StaticMutex.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/UniquePtrExtensions.h"
#include "mozilla/ipc/SharedMemoryHandle.h"
#include "nsComponentManagerUtils.h"
#include "nsPrintfCString.h"
#include "nsString.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
#include "nsDirectoryServiceDefs.h"
#include "nsAppDirectoryServiceDefs.h"
#include "SpecialSystemDirectory.h"
#include "nsReadableUtils.h"
#include "nsIFileStreams.h"
#include "nsILineInputStream.h"
#include "nsIFile.h"
#include "nsNetCID.h"
#include "prenv.h"
#if defined(MOZ_PROFILE_GENERATE)
# include <string>
#endif
#ifdef ANDROID
# include "cutils/properties.h"
#endif
#ifdef MOZ_WIDGET_GTK
# include "mozilla/WidgetUtilsGtk.h"
# include <glib.h>
#endif
#ifdef MOZ_ENABLE_V4L2
# include <linux/videodev2.h>
# include <sys/ioctl.h>
# include <fcntl.h>
#endif // MOZ_ENABLE_V4L2
#include <dirent.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#ifndef ANDROID
# include <glob.h>
#endif
namespace mozilla {
namespace {
static const int rdonly = SandboxBroker::MAY_READ;
static const int wronly = SandboxBroker::MAY_WRITE;
static const int rdwr = rdonly | wronly;
static const int rdwrcr = rdwr | SandboxBroker::MAY_CREATE;
static const int access = SandboxBroker::MAY_ACCESS;
static const int deny = SandboxBroker::FORCE_DENY;
} // namespace
using CacheE = std::pair<nsCString, int>;
using FileCacheT = nsTArray<CacheE>;
static void AddDriPaths(SandboxBroker::Policy* aPolicy) {
// Bug 1401666: Mesa driver loader part 2: Mesa <= 12 using libudev
// Used by libdrm, which is used by Mesa, and
// Intel(R) Media Driver for VAAPI.
if (auto dir = opendir("/dev/dri")) {
while (auto entry = readdir(dir)) {
if (entry->d_name[0] != '.') {
nsPrintfCString devPath("/dev/dri/%s", entry->d_name);
struct stat sb;
if (stat(devPath.get(), &sb) == 0 && S_ISCHR(sb.st_mode)) {
// For both the DRI node and its parent (the physical
// device), allow reading the "uevent" file.
static const Array<nsCString, 2> kSuffixes = {""_ns, "/device"_ns};
nsPrintfCString prefix("/sys/dev/char/%u:%u", major(sb.st_rdev),
minor(sb.st_rdev));
for (const auto& suffix : kSuffixes) {
nsCString sysPath(prefix + suffix);
// libudev will expand the symlink but not do full
// canonicalization, so it will leave in ".." path
// components that will be realpath()ed in the
// broker. To match this, allow the canonical paths.
UniqueFreePtr<char[]> realSysPath(realpath(sysPath.get(), nullptr));
if (realSysPath) {
// https://gitlab.freedesktop.org/mesa/drm/-/commit/3988580e4c0f4b3647a0c6af138a3825453fe6e0
// > term = strrchr(real_path, '/');
// > if (term && strncmp(term, "/virtio", 7) == 0)
// > *term = 0;
char* term = strrchr(realSysPath.get(), '/');
if (term && strncmp(term, "/virtio", 7) == 0) {
*term = 0;
}
aPolicy->AddFilePrefix(rdonly, realSysPath.get(), "");
// Allowing stat-ing and readlink-ing the parent dirs
nsPrintfCString basePath("%s/", realSysPath.get());
aPolicy->AddAncestors(basePath.get(), rdonly);
}
}
// https://gitlab.freedesktop.org/mesa/drm/-/commit/a02900133b32dd4a7d6da4966f455ab337e80dfc
// > strncpy(path, device_path, PATH_MAX);
// > strncat(path, "/subsystem", PATH_MAX);
// >
// > if (readlink(path, link, PATH_MAX) < 0)
// > return -errno;
nsCString subsystemPath(prefix + "/device/subsystem"_ns);
aPolicy->AddPath(rdonly, subsystemPath.get());
aPolicy->AddAncestors(subsystemPath.get(), rdonly);
}
}
}
closedir(dir);
}
// https://gitlab.freedesktop.org/mesa/mesa/-/commit/04bdbbcab3c4862bf3f54ce60fcc1d2007776f80
aPolicy->AddPath(rdonly, "/usr/share/drirc.d");
// https://dri.freedesktop.org/wiki/ConfigurationInfrastructure/
aPolicy->AddPath(rdonly, "/etc/drirc");
nsCOMPtr<nsIFile> drirc;
nsresult rv =
GetSpecialSystemDirectory(Unix_HomeDirectory, getter_AddRefs(drirc));
if (NS_SUCCEEDED(rv)) {
rv = drirc->AppendNative(".drirc"_ns);
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = drirc->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
aPolicy->AddPath(rdonly, tmpPath.get());
}
}
}
}
static void JoinPathIfRelative(const nsACString& aCwd, const nsACString& inPath,
nsACString& outPath) {
if (inPath.Length() < 1) {
outPath.Assign(aCwd);
SANDBOX_LOG("Unjoinable path: %s", PromiseFlatCString(aCwd).get());
return;
}
const char* startChar = inPath.BeginReading();
if (*startChar != '/') {
// Relative path, copy basepath in front
outPath.Assign(aCwd);
outPath.Append("/");
outPath.Append(inPath);
} else {
// Absolute path, it's ok like this
outPath.Assign(inPath);
}
}
static void CachePathsFromFile(FileCacheT& aCache, const nsACString& aPath);
static void CachePathsFromFileInternal(FileCacheT& aCache,
const nsACString& aCwd,
const nsACString& aPath) {
nsresult rv;
nsCOMPtr<nsIFile> ldconfig;
rv = NS_NewNativeLocalFile(aPath, getter_AddRefs(ldconfig));
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
nsCOMPtr<nsIFileInputStream> fileStream(
do_CreateInstance(NS_LOCALFILEINPUTSTREAM_CONTRACTID, &rv));
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
rv = fileStream->Init(ldconfig, -1, -1, 0);
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
nsCOMPtr<nsILineInputStream> lineStream(do_QueryInterface(fileStream, &rv));
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
nsAutoCString line;
bool more = true;
do {
rv = lineStream->ReadLine(line, &more);
if (NS_FAILED(rv)) {
break;
}
// Cut off any comments at the end of the line, also catches lines
// that are entirely a comment
int32_t hash = line.FindChar('#');
if (hash >= 0) {
line = Substring(line, 0, hash);
}
// Simplify our following parsing by trimming whitespace
line.CompressWhitespace(true, true);
if (line.IsEmpty()) {
// Skip comment lines
continue;
}
// Check for any included files and recursively process
nsACString::const_iterator start, end, token_end;
line.BeginReading(start);
line.EndReading(end);
token_end = end;
if (FindInReadable("include "_ns, start, token_end)) {
nsAutoCString includes(Substring(token_end, end));
for (const nsACString& includeGlob : includes.Split(' ')) {
// Glob path might be relative, so add cwd if so.
nsAutoCString includeFile;
JoinPathIfRelative(aCwd, includeGlob, includeFile);
glob_t globbuf;
if (!glob(PromiseFlatCString(includeFile).get(), GLOB_NOSORT, nullptr,
&globbuf)) {
for (size_t fileIdx = 0; fileIdx < globbuf.gl_pathc; fileIdx++) {
nsAutoCString filePath(globbuf.gl_pathv[fileIdx]);
CachePathsFromFile(aCache, filePath);
}
globfree(&globbuf);
}
}
}
// Cut off anything behind an = sign, used by dirname=TYPE directives
int32_t equals = line.FindChar('=');
if (equals >= 0) {
line = Substring(line, 0, equals);
}
char* resolvedPath = realpath(line.get(), nullptr);
if (resolvedPath) {
aCache.AppendElement(std::make_pair(nsCString(resolvedPath), rdonly));
free(resolvedPath);
}
} while (more);
}
static void CachePathsFromFile(FileCacheT& aCache, const nsACString& aPath) {
// Find the new base path where that file sits in.
nsresult rv;
nsCOMPtr<nsIFile> includeFile;
rv = NS_NewNativeLocalFile(aPath, getter_AddRefs(includeFile));
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
if (SandboxInfo::Get().Test(SandboxInfo::kVerbose)) {
SANDBOX_LOG("Adding paths from %s to policy.",
PromiseFlatCString(aPath).get());
}
// Find the parent dir where this file sits in.
nsCOMPtr<nsIFile> parentDir;
rv = includeFile->GetParent(getter_AddRefs(parentDir));
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
nsAutoCString parentPath;
rv = parentDir->GetNativePath(parentPath);
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
if (SandboxInfo::Get().Test(SandboxInfo::kVerbose)) {
SANDBOX_LOG("Parent path is %s", PromiseFlatCString(parentPath).get());
}
CachePathsFromFileInternal(aCache, parentPath, aPath);
}
static void AddLdconfigPaths(SandboxBroker::Policy* aPolicy) {
static StaticMutex sMutex;
StaticMutexAutoLock lock(sMutex);
static FileCacheT ldConfigCache{};
static bool ldConfigCachePopulated = false;
if (!ldConfigCachePopulated) {
CachePathsFromFile(ldConfigCache, "/etc/ld.so.conf"_ns);
ldConfigCachePopulated = true;
RunOnShutdown([&] {
ldConfigCache.Clear();
MOZ_ASSERT(ldConfigCache.IsEmpty(), "ldconfig cache should be empty");
});
}
for (const CacheE& e : ldConfigCache) {
aPolicy->AddTree(e.second, e.first.get());
}
}
static void AddLdLibraryEnvPaths(SandboxBroker::Policy* aPolicy) {
nsAutoCString LdLibraryEnv(PR_GetEnv("LD_LIBRARY_PATH"));
// The items in LD_LIBRARY_PATH can be separated by either colons or
// semicolons, according to the ld.so(8) man page, and empirically it
// seems to be allowed to mix them (i.e., a:b;c is a list with 3 elements).
// There is no support for escaping the delimiters, fortunately (for us).
LdLibraryEnv.ReplaceChar(';', ':');
for (const nsACString& libPath : LdLibraryEnv.Split(':')) {
char* resolvedPath = realpath(PromiseFlatCString(libPath).get(), nullptr);
if (resolvedPath) {
aPolicy->AddTree(rdonly, resolvedPath);
free(resolvedPath);
}
}
}
static void AddSharedMemoryPaths(SandboxBroker::Policy* aPolicy, pid_t aPid) {
std::string shmPath("/dev/shm");
if (ipc::shared_memory::AppendPosixShmPrefix(&shmPath, aPid)) {
aPolicy->AddPrefix(rdwrcr, shmPath.c_str());
}
}
static void AddMemoryReporting(SandboxBroker::Policy* aPolicy, pid_t aPid) {
// Bug 1198552: memory reporting.
// Bug 1647957: memory reporting.
aPolicy->AddPath(rdonly, nsPrintfCString("/proc/%d/statm", aPid).get());
aPolicy->AddPath(rdonly, nsPrintfCString("/proc/%d/smaps", aPid).get());
}
static void AddDynamicPathList(SandboxBroker::Policy* policy,
const char* aPathListPref, int perms) {
nsAutoCString pathList;
nsresult rv = Preferences::GetCString(aPathListPref, pathList);
if (NS_SUCCEEDED(rv)) {
for (const nsACString& path : pathList.Split(',')) {
nsCString trimPath(path);
trimPath.Trim(" ", true, true);
policy->AddDynamic(perms, trimPath.get());
}
}
}
static void AddX11Dependencies(SandboxBroker::Policy* policy) {
// Allow Primus to contact the Bumblebee daemon to manage GPU
// switching on NVIDIA Optimus systems.
const char* bumblebeeSocket = PR_GetEnv("BUMBLEBEE_SOCKET");
if (bumblebeeSocket == nullptr) {
bumblebeeSocket = "/var/run/bumblebee.socket";
}
policy->AddPath(SandboxBroker::MAY_CONNECT, bumblebeeSocket);
#if defined(MOZ_WIDGET_GTK) && defined(MOZ_X11)
// Allow local X11 connections, for several purposes:
//
// * for content processes to use WebGL when the browser is in headless
// mode, by opening the X display if/when needed
//
// * if Primus or VirtualGL is used, to contact the secondary X server
static const bool kIsX11 =
!mozilla::widget::GdkIsWaylandDisplay() && PR_GetEnv("DISPLAY");
if (kIsX11) {
policy->AddPrefix(SandboxBroker::MAY_CONNECT, "/tmp/.X11-unix/X");
if (auto* const xauth = PR_GetEnv("XAUTHORITY")) {
policy->AddPath(rdonly, xauth);
} else if (auto* const home = PR_GetEnv("HOME")) {
// This follows the logic in libXau: append "/.Xauthority",
// even if $HOME ends in a slash, except in the special case
// where HOME=/ because POSIX allows implementations to treat
// an initial double slash specially.
nsAutoCString xauth(home);
if (xauth != "/"_ns) {
xauth.Append('/');
}
xauth.AppendLiteral(".Xauthority");
policy->AddPath(rdonly, xauth.get());
}
}
#endif
}
static void AddGLDependencies(SandboxBroker::Policy* policy) {
// Devices
policy->AddTree(rdwr, "/dev/dri");
policy->AddFilePrefix(rdwr, "/dev", "nvidia");
// Hardware info
AddDriPaths(policy);
// /etc and /usr/share (glvnd, libdrm, drirc, ...?)
policy->AddTree(rdonly, "/etc");
policy->AddTree(rdonly, "/usr/share");
policy->AddTree(rdonly, "/usr/local/share");
// Snap puts the usual /usr/share things in a different place, and
// we'll fail to load the library if we don't have (at least) the
// glvnd config:
if (const char* snapDesktopDir = PR_GetEnv("SNAP_DESKTOP_RUNTIME")) {
nsAutoCString snapDesktopShare(snapDesktopDir);
snapDesktopShare.AppendLiteral("/usr/share");
policy->AddTree(rdonly, snapDesktopShare.get());
}
// Introduced by Snap's core24 changes there is a gpu-2404 dependency and
// it is recommended to allow access to all of it?
if (const char* snapRoot = PR_GetEnv("SNAP")) {
nsAutoCString snapRootString(snapRoot);
snapRootString.AppendLiteral("/gpu-2404");
policy->AddTree(rdonly, snapRootString.get());
}
// Note: This function doesn't do anything about Mesa's shader
// cache, because the details can vary by process type, including
// whether caching is enabled.
// This also doesn't include permissions for connecting to a display
// server, because headless GL (e.g., Mesa GBM) may not need it.
}
// Assums this is an absolute path, SandboxBroker does not like relative paths:
// RealPath() will try to get the absolute path of the llvm profile path to open
// for writing but this will return errno=2 because the file does not exists, so
// sandbox will not allow for its creation.
//
// Forcing expecting an absolute path will be enough to make sure it can be
// allowed.
//
// It should only be allowed on instrumented builds, never on production
// builds.
#if defined(MOZ_PROFILE_GENERATE)
static void AddLLVMProfilePathDirectory(SandboxBroker::Policy* aPolicy) {
std::string parentPath;
if (GetLlvmProfileDir(parentPath)) {
aPolicy->AddFutureDir(rdwrcr, parentPath.c_str());
}
}
#endif // defined(MOZ_PROFILE_GENERATE)
// Make sure the path read from environment is correct (absolute).
const char* PathFromEnvIfAbsolute(const char* aPath) {
const char* envValue = PR_GetEnv(aPath);
if (envValue && envValue[0] == '/') {
return envValue;
}
return nullptr;
}
void SandboxBrokerPolicyFactory::InitContentPolicy() {
const int level = GetEffectiveContentSandboxLevel();
const bool headless = level >= 5;
// Policy entries that are the same in every process go here, and
// are cached over the lifetime of the factory.
SandboxBroker::Policy* policy = new SandboxBroker::Policy;
// Write permssions
// Bug 1575985: WASM library sandbox needs RW access to /dev/null
policy->AddPath(rdwr, "/dev/null");
if (!headless) {
AddGLDependencies(policy);
AddX11Dependencies(policy);
}
// Read permissions
policy->AddPath(rdonly, "/dev/urandom");
policy->AddPath(rdonly, "/dev/random");
policy->AddPath(rdonly, "/proc/sys/crypto/fips_enabled");
policy->AddPath(rdonly, "/proc/cpuinfo");
policy->AddPath(rdonly, "/proc/meminfo");
policy->AddTree(rdonly, "/sys/devices/cpu");
policy->AddTree(rdonly, "/sys/devices/system/cpu");
policy->AddTree(rdonly, "/lib");
policy->AddTree(rdonly, "/lib64");
policy->AddTree(rdonly, "/usr/lib");
policy->AddTree(rdonly, "/usr/lib32");
policy->AddTree(rdonly, "/usr/lib64");
policy->AddTree(rdonly, "/etc");
policy->AddTree(rdonly, "/usr/share");
policy->AddTree(rdonly, "/usr/local/share");
// Various places where fonts reside
policy->AddTree(rdonly, "/usr/X11R6/lib/X11/fonts");
policy->AddTree(rdonly, "/nix/store");
// https://gitlab.com/freedesktop-sdk/freedesktop-sdk/-/blob/e434e680d22260f277f4a30ec4660ed32b591d16/files/fontconfig-flatpak.conf
policy->AddTree(rdonly, "/run/host/fonts");
policy->AddTree(rdonly, "/run/host/user-fonts");
policy->AddTree(rdonly, "/run/host/local-fonts");
policy->AddTree(rdonly, "/var/cache/fontconfig");
// Bug 1848615
policy->AddPath(rdonly, "/usr");
policy->AddPath(rdonly, "/nix");
AddLdconfigPaths(policy);
AddLdLibraryEnvPaths(policy);
if (!headless) {
// Bug 1385715: NVIDIA PRIME support
policy->AddPath(rdonly, "/proc/modules");
}
// XDG directories might be non existent according to specs:
// https://specifications.freedesktop.org/basedir-spec/0.8/ar01s04.html
//
// > If, when attempting to write a file, the destination directory is
// > non-existent an attempt should be made to create it with permission 0700.
//
// For that we use AddPath(, SandboxBroker::Policy::AddCondition::AddAlways).
//
// Allow access to XDG_CONFIG_HOME and XDG_CONFIG_DIRS
nsAutoCString xdgConfigHome(PathFromEnvIfAbsolute("XDG_CONFIG_HOME"));
if (!xdgConfigHome.IsEmpty()) { // AddPath will fail on empty strings
policy->AddFutureDir(rdonly, xdgConfigHome.get());
}
nsAutoCString xdgConfigDirs(PR_GetEnv("XDG_CONFIG_DIRS"));
for (const auto& path : xdgConfigDirs.Split(':')) {
if (path[0] != '/') {
continue;
}
if (!path.IsEmpty()) { // AddPath will fail on empty strings
policy->AddFutureDir(rdonly, PromiseFlatCString(path).get());
}
}
// Allow fonts subdir in XDG_DATA_HOME
nsAutoCString xdgDataHome(PathFromEnvIfAbsolute("XDG_DATA_HOME"));
if (!xdgDataHome.IsEmpty()) {
nsAutoCString fontPath(xdgDataHome);
fontPath.Append("/fonts");
policy->AddFutureDir(rdonly, PromiseFlatCString(fontPath).get());
}
// Any font subdirs in XDG_DATA_DIRS
nsAutoCString xdgDataDirs(PR_GetEnv("XDG_DATA_DIRS"));
for (const auto& path : xdgDataDirs.Split(':')) {
if (path[0] != '/') {
continue;
}
nsAutoCString fontPath(path);
fontPath.Append("/fonts");
policy->AddFutureDir(rdonly, PromiseFlatCString(fontPath).get());
}
// Extra configuration/cache dirs in the homedir that we want to allow read
// access to.
std::vector<const char*> extraConfDirsAllow = {
".themes",
".fonts",
".cache/fontconfig",
};
// Fallback if XDG_CONFIG_HOME isn't set
if (xdgConfigHome.IsEmpty()) {
extraConfDirsAllow.emplace_back(".config");
}
nsCOMPtr<nsIFile> homeDir;
nsresult rv =
GetSpecialSystemDirectory(Unix_HomeDirectory, getter_AddRefs(homeDir));
if (NS_SUCCEEDED(rv)) {
nsCOMPtr<nsIFile> confDir;
for (const auto& dir : extraConfDirsAllow) {
rv = homeDir->Clone(getter_AddRefs(confDir));
if (NS_SUCCEEDED(rv)) {
rv = confDir->AppendRelativeNativePath(nsDependentCString(dir));
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = confDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddTree(rdonly, tmpPath.get());
}
}
}
}
// ~/.config/mozilla/ needs to be manually blocked, because the previous
// loop will allow for ~/.config/ access.
{
// If $XDG_CONFIG_HOME is set, we need to account for it.
// FIXME: Bug 1722272: Maybe this should just be handled with
// GetSpecialSystemDirectory(Unix_XDG_ConfigHome) ?
nsCOMPtr<nsIFile> confDirOrXDGConfigHomeDir;
if (!xdgConfigHome.IsEmpty()) {
rv = NS_NewNativeLocalFile(xdgConfigHome,
getter_AddRefs(confDirOrXDGConfigHomeDir));
// confDirOrXDGConfigHomeDir = nsIFile($XDG_CONFIG_HOME)
} else {
rv = homeDir->Clone(getter_AddRefs(confDirOrXDGConfigHomeDir));
if (NS_SUCCEEDED(rv)) {
// since we will use that later, we dont need to care about trailing
// slash
rv = confDirOrXDGConfigHomeDir->AppendNative(".config"_ns);
// confDirOrXDGConfigHomeDir = nsIFile($HOME/.config/)
}
}
if (NS_SUCCEEDED(rv)) {
rv = confDirOrXDGConfigHomeDir->AppendNative("mozilla"_ns);
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = confDirOrXDGConfigHomeDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddFutureDir(deny, tmpPath.get());
}
}
}
}
// ~/.local/share (for themes)
rv = homeDir->Clone(getter_AddRefs(confDir));
if (NS_SUCCEEDED(rv)) {
rv = confDir->AppendNative(".local"_ns);
if (NS_SUCCEEDED(rv)) {
rv = confDir->AppendNative("share"_ns);
}
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = confDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddTree(rdonly, tmpPath.get());
}
}
}
// ~/.fonts.conf (Fontconfig)
rv = homeDir->Clone(getter_AddRefs(confDir));
if (NS_SUCCEEDED(rv)) {
rv = confDir->AppendNative(".fonts.conf"_ns);
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = confDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddPath(rdonly, tmpPath.get());
}
}
}
// .pangorc
rv = homeDir->Clone(getter_AddRefs(confDir));
if (NS_SUCCEEDED(rv)) {
rv = confDir->AppendNative(".pangorc"_ns);
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = confDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddPath(rdonly, tmpPath.get());
}
}
}
}
// Firefox binary dir.
// Note that unlike the previous cases, we use NS_GetSpecialDirectory
// instead of GetSpecialSystemDirectory. The former requires a working XPCOM
// system, which may not be the case for some tests. For querying for the
// location of XPCOM things, we can use it anyway.
nsCOMPtr<nsIFile> ffDir;
rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(ffDir));
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = ffDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddTree(rdonly, tmpPath.get());
}
}
if (!mozilla::IsPackagedBuild()) {
// If this is not a packaged build the resources are likely symlinks to
// outside the binary dir. Therefore in non-release builds we allow reads
// from the whole repository. MOZ_DEVELOPER_REPO_DIR is set by mach run.
const char* developer_repo_dir = PR_GetEnv("MOZ_DEVELOPER_REPO_DIR");
if (developer_repo_dir) {
policy->AddTree(rdonly, developer_repo_dir);
}
}
#ifdef DEBUG
char* bloatLog = PR_GetEnv("XPCOM_MEM_BLOAT_LOG");
// XPCOM_MEM_BLOAT_LOG has the format
// /tmp/tmpd0YzFZ.mozrunner/runtests_leaks.log
// but stores into /tmp/tmpd0YzFZ.mozrunner/runtests_leaks_tab_pid3411.log
// So cut the .log part and whitelist the prefix.
if (bloatLog != nullptr) {
size_t bloatLen = strlen(bloatLog);
if (bloatLen >= 4) {
nsAutoCString bloatStr(bloatLog);
bloatStr.Truncate(bloatLen - 4);
policy->AddPrefix(rdwrcr, bloatStr.get());
}
}
#endif
if (!headless) {
AddX11Dependencies(policy);
}
// Bug 1732580: when packaged as a strictly confined snap, may need
// read-access to configuration files under $SNAP/.
const char* snap = PR_GetEnv("SNAP");
if (snap) {
// When running as a snap, the directory pointed to by $SNAP is guaranteed
// to exist before the app is launched, but unit tests need to create it
// dynamically, hence the use of AddFutureDir().
policy->AddTree(rdonly, snap);
}
// Read any extra paths that will get write permissions,
// configured by the user or distro
AddDynamicPathList(policy, "security.sandbox.content.write_path_whitelist",
rdwr);
// Whitelisted for reading by the user/distro
AddDynamicPathList(policy, "security.sandbox.content.read_path_whitelist",
rdonly);
// userContent.css and the extensions dir sit in the profile, which is
// normally blocked.
nsCOMPtr<nsIFile> profileDir;
rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
getter_AddRefs(profileDir));
if (NS_SUCCEEDED(rv)) {
nsCOMPtr<nsIFile> workDir;
rv = profileDir->Clone(getter_AddRefs(workDir));
if (NS_SUCCEEDED(rv)) {
rv = workDir->AppendNative("chrome"_ns);
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = workDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddTree(rdonly, tmpPath.get());
}
}
}
rv = profileDir->Clone(getter_AddRefs(workDir));
if (NS_SUCCEEDED(rv)) {
rv = workDir->AppendNative("extensions"_ns);
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = workDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
bool exists;
rv = workDir->Exists(&exists);
if (NS_SUCCEEDED(rv)) {
if (!exists) {
policy->AddPrefix(rdonly, tmpPath.get());
policy->AddPath(rdonly, tmpPath.get());
} else {
policy->AddTree(rdonly, tmpPath.get());
}
}
}
}
}
}
bool allowPulse = false;
bool allowAlsa = false;
if (level < 4) {
#ifdef MOZ_PULSEAUDIO
allowPulse = true;
#endif
#ifdef MOZ_ALSA
allowAlsa = true;
#endif
}
if (allowAlsa) {
// Bug 1309098: ALSA support
policy->AddTree(rdwr, "/dev/snd");
}
if (allowPulse) {
policy->AddTree(rdwrcr, "/dev/shm");
}
#ifdef MOZ_WIDGET_GTK
if (const auto userDir = g_get_user_runtime_dir()) {
// Bug 1321134: DConf's single bit of shared memory
// The leaf filename is "user" by default, but is configurable.
nsPrintfCString shmPath("%s/dconf/", userDir);
policy->AddPrefix(rdwrcr, shmPath.get());
policy->AddAncestors(shmPath.get());
if (allowPulse) {
// PulseAudio, if it can't get server info from X11, will break
// unless it can open this directory (or create it, but in our use
// case we know it already exists). See bug 1335329.
nsPrintfCString pulsePath("%s/pulse", userDir);
policy->AddPath(rdonly, pulsePath.get());
}
}
#endif // MOZ_WIDGET_GTK
if (allowPulse) {
// PulseAudio also needs access to read the $XAUTHORITY file (see
// bug 1384986 comment #1), but that's already allowed for hybrid
// GPU drivers (see above).
policy->AddPath(rdonly, "/var/lib/dbus/machine-id");
}
// Bug 1434711 - AMDGPU-PRO crashes if it can't read it's marketing ids
// and various other things
if (!headless && HasAtiDrivers()) {
policy->AddTree(rdonly, "/opt/amdgpu/share");
policy->AddPath(rdonly, "/sys/module/amdgpu");
}
#if defined(MOZ_PROFILE_GENERATE)
AddLLVMProfilePathDirectory(policy);
#endif
mCommonContentPolicy.reset(policy);
}
UniquePtr<SandboxBroker::Policy> SandboxBrokerPolicyFactory::GetContentPolicy(
int aPid, bool aFileProcess) {
// Policy entries that vary per-process (because they depend on the
// pid or content subtype) are added here.
MOZ_ASSERT(NS_IsMainThread());
const int level = GetEffectiveContentSandboxLevel();
// The file broker is used at level 2 and up.
if (level <= 1) {
// Level 1 has been removed.
MOZ_ASSERT(level == 0);
return nullptr;
}
std::call_once(mContentInited, [this] { InitContentPolicy(); });
MOZ_ASSERT(mCommonContentPolicy);
UniquePtr<SandboxBroker::Policy> policy(
new SandboxBroker::Policy(*mCommonContentPolicy));
// No read blocking at level 2 and below.
// file:// processes also get global read permissions
if (level <= 2 || aFileProcess) {
policy->AddTree(rdonly, "/");
// Any other read-only rules will be removed as redundant by
// Policy::FixRecursivePermissions, so there's no need to
// early-return here.
}
// Access to /dev/shm is restricted to a per-process prefix to
// prevent interfering with other processes or with services outside
// the browser (e.g., PulseAudio).
AddSharedMemoryPaths(policy.get(), aPid);
// Bug 1198550: the profiler's replacement for dl_iterate_phdr
policy->AddPath(rdonly, nsPrintfCString("/proc/%d/maps", aPid).get());
// Bug 1736040: CPU use telemetry
policy->AddPath(rdonly, nsPrintfCString("/proc/%d/stat", aPid).get());
// Bug 1198552: memory reporting.
AddMemoryReporting(policy.get(), aPid);
// Bug 1384804, notably comment 15
// Used by libnuma, included by x265/ffmpeg, who falls back
// to get_mempolicy if this fails
policy->AddPath(rdonly, nsPrintfCString("/proc/%d/status", aPid).get());
// Finalize the policy.
policy->FixRecursivePermissions();
return policy;
}
#ifdef MOZ_ENABLE_V4L2
static void AddV4l2Dependencies(SandboxBroker::Policy* policy) {
// For V4L2 hardware-accelerated video decode, RDD needs access to certain
// /dev/video* devices but don't want to allow it access to webcams etc.
// So we only allow it access to M2M video devices (encoders and decoders).
DIR* dir = opendir("/dev");
if (!dir) {
SANDBOX_LOG("Couldn't list /dev");
return;
}
struct dirent* dir_entry;
while ((dir_entry = readdir(dir))) {
if (strncmp(dir_entry->d_name, "video", 5)) {
// Not a /dev/video* device, so ignore it
continue;
}
nsCString path = "/dev/"_ns;
path += nsDependentCString(dir_entry->d_name);
int fd = open(path.get(), O_RDWR | O_NONBLOCK, 0);
if (fd < 0) {
// Couldn't open this device, so ignore it.
SANDBOX_LOG("Couldn't open video device %s", path.get());
continue;
}
// Query device capabilities
struct v4l2_capability cap;
int result = ioctl(fd, VIDIOC_QUERYCAP, &cap);
if (result < 0) {
// Couldn't query capabilities of this device, so ignore it
SANDBOX_LOG("Couldn't query capabilities of video device %s", path.get());
close(fd);
continue;
}
if ((cap.device_caps & V4L2_CAP_VIDEO_M2M) ||
(cap.device_caps & V4L2_CAP_VIDEO_M2M_MPLANE)) {
// This is an M2M device (i.e. not a webcam), so allow access
policy->AddPath(rdwr, path.get());
}
close(fd);
}
closedir(dir);
// FFmpeg V4L2 needs to list /dev to find V4L2 devices.
policy->AddPath(rdonly, "/dev");
}
#endif // MOZ_ENABLE_V4L2
/* static */ UniquePtr<SandboxBroker::Policy>
SandboxBrokerPolicyFactory::GetRDDPolicy(int aPid) {
auto policy = MakeUnique<SandboxBroker::Policy>();
AddSharedMemoryPaths(policy.get(), aPid);
policy->AddPath(rdonly, "/dev/urandom");
// FIXME (bug 1662321): we should fix nsSystemInfo so that every
// child process doesn't need to re-read these files to get the info
// the parent process already has.
policy->AddPath(rdonly, "/proc/cpuinfo");
policy->AddPath(rdonly,
"/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq");
policy->AddPath(rdonly, "/sys/devices/system/cpu/cpu0/cache/index2/size");
policy->AddPath(rdonly, "/sys/devices/system/cpu/cpu0/cache/index3/size");
policy->AddTree(rdonly, "/sys/devices/cpu");
policy->AddTree(rdonly, "/sys/devices/system/cpu");
policy->AddTree(rdonly, "/sys/devices/system/node");
policy->AddTree(rdonly, "/lib");
policy->AddTree(rdonly, "/lib64");
policy->AddTree(rdonly, "/usr/lib");
policy->AddTree(rdonly, "/usr/lib32");
policy->AddTree(rdonly, "/usr/lib64");
policy->AddTree(rdonly, "/run/opengl-driver/lib");
policy->AddTree(rdonly, "/nix/store");
// Bug 1647957: memory reporting.
AddMemoryReporting(policy.get(), aPid);
// Firefox binary dir.
// Note that unlike the previous cases, we use NS_GetSpecialDirectory
// instead of GetSpecialSystemDirectory. The former requires a working XPCOM
// system, which may not be the case for some tests. For querying for the
// location of XPCOM things, we can use it anyway.
nsCOMPtr<nsIFile> ffDir;
nsresult rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(ffDir));
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = ffDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddTree(rdonly, tmpPath.get());
}
}
if (!mozilla::IsPackagedBuild()) {
// If this is not a packaged build the resources are likely symlinks to
// outside the binary dir. Therefore in non-release builds we allow reads
// from the whole repository. MOZ_DEVELOPER_REPO_DIR is set by mach run.
const char* developer_repo_dir = PR_GetEnv("MOZ_DEVELOPER_REPO_DIR");
if (developer_repo_dir) {
policy->AddTree(rdonly, developer_repo_dir);
}
}
// VA-API needs GPU access and GL context creation (but not display
// server access, as of bug 1769499).
AddGLDependencies(policy.get());
// FFmpeg and GPU drivers may need general-case library loading
AddLdconfigPaths(policy.get());
AddLdLibraryEnvPaths(policy.get());
#ifdef MOZ_ENABLE_V4L2
AddV4l2Dependencies(policy.get());
#endif // MOZ_ENABLE_V4L2
// Bug 1903688: NVIDIA Tegra hardware decoding from Linux4Tegra
// Only built on ARM64 since Tegra is ARM64 SoC with different drivers, so the
// path are not needed on e.g. x86-64
#if defined(__aarch64__)
policy->AddTree(rdonly, "/sys/devices/system/present");
policy->AddTree(rdonly, "/sys/module/tegra_fuse");
policy->AddPath(rdwr, "/dev/nvmap");
policy->AddPath(rdwr, "/dev/nvhost-ctrl");
policy->AddPath(rdwr, "/dev/nvhost-ctrl-gpu");
policy->AddPath(rdwr, "/dev/nvhost-nvdec");
policy->AddPath(rdwr, "/dev/nvhost-nvdec1");
policy->AddPath(rdwr, "/dev/nvhost-vic");
#endif // defined(__aarch64__)
#if defined(MOZ_PROFILE_GENERATE)
AddLLVMProfilePathDirectory(policy.get());
#endif
if (policy->IsEmpty()) {
policy = nullptr;
}
return policy;
}
/* static */ UniquePtr<SandboxBroker::Policy>
SandboxBrokerPolicyFactory::GetSocketProcessPolicy(int aPid) {
auto policy = MakeUnique<SandboxBroker::Policy>();
policy->AddPath(rdonly, "/dev/urandom");
policy->AddPath(rdonly, "/dev/random");
policy->AddPath(rdonly, "/proc/sys/crypto/fips_enabled");
policy->AddPath(rdonly, "/proc/cpuinfo");
policy->AddPath(rdonly, "/proc/meminfo");
policy->AddTree(rdonly, "/sys/devices/cpu");
policy->AddTree(rdonly, "/sys/devices/system/cpu");
policy->AddTree(rdonly, "/lib");
policy->AddTree(rdonly, "/lib64");
policy->AddTree(rdonly, "/usr/lib");
policy->AddTree(rdonly, "/usr/lib32");
policy->AddTree(rdonly, "/usr/lib64");
policy->AddTree(rdonly, "/usr/share");
policy->AddTree(rdonly, "/usr/local/share");
policy->AddTree(rdonly, "/etc");
// glibc will try to stat64("/") while populating nsswitch database
// https://sourceware.org/git/?p=glibc.git;a=blob;f=nss/nss_database.c;h=cf0306adc47f12d9bc761ab1b013629f4482b7e6;hb=9826b03b747b841f5fc6de2054bf1ef3f5c4bdf3#l396
// denying will make getaddrinfo() return ENONAME
policy->AddPath(access, "/");
AddLdconfigPaths(policy.get());
// Socket process sandbox needs to allow shmem in order to support
// profiling. See Bug 1626385.
AddSharedMemoryPaths(policy.get(), aPid);
// Bug 1647957: memory reporting.
AddMemoryReporting(policy.get(), aPid);
// Firefox binary dir.
// Note that unlike the previous cases, we use NS_GetSpecialDirectory
// instead of GetSpecialSystemDirectory. The former requires a working XPCOM
// system, which may not be the case for some tests. For querying for the
// location of XPCOM things, we can use it anyway.
nsCOMPtr<nsIFile> ffDir;
nsresult rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(ffDir));
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = ffDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddTree(rdonly, tmpPath.get());
}
}
#if defined(MOZ_PROFILE_GENERATE)
AddLLVMProfilePathDirectory(policy.get());
#endif
if (policy->IsEmpty()) {
policy = nullptr;
}
return policy;
}
/* static */ UniquePtr<SandboxBroker::Policy>
SandboxBrokerPolicyFactory::GetUtilityProcessPolicy(int aPid) {
auto policy = MakeUnique<SandboxBroker::Policy>();
policy->AddPath(rdonly, "/dev/urandom");
policy->AddPath(rdonly, "/proc/cpuinfo");
policy->AddPath(rdonly, "/proc/meminfo");
policy->AddPath(rdonly, nsPrintfCString("/proc/%d/exe", aPid).get());
policy->AddTree(rdonly, "/sys/devices/cpu");
policy->AddTree(rdonly, "/sys/devices/system/cpu");
policy->AddTree(rdonly, "/lib");
policy->AddTree(rdonly, "/lib64");
policy->AddTree(rdonly, "/usr/lib");
policy->AddTree(rdonly, "/usr/lib32");
policy->AddTree(rdonly, "/usr/lib64");
policy->AddTree(rdonly, "/usr/share");
policy->AddTree(rdonly, "/usr/local/share");
policy->AddTree(rdonly, "/etc");
// Required to make sure ffmpeg loads properly, this is already existing on
// Content and RDD
policy->AddTree(rdonly, "/nix/store");
// glibc will try to stat64("/") while populating nsswitch database
// https://sourceware.org/git/?p=glibc.git;a=blob;f=nss/nss_database.c;h=cf0306adc47f12d9bc761ab1b013629f4482b7e6;hb=9826b03b747b841f5fc6de2054bf1ef3f5c4bdf3#l396
// denying will make getaddrinfo() return ENONAME
policy->AddPath(access, "/");
AddLdconfigPaths(policy.get());
AddLdLibraryEnvPaths(policy.get());
// Utility process sandbox needs to allow shmem in order to support
// profiling. See Bug 1626385.
AddSharedMemoryPaths(policy.get(), aPid);
// Bug 1647957: memory reporting.
AddMemoryReporting(policy.get(), aPid);
// Firefox binary dir.
// Note that unlike the previous cases, we use NS_GetSpecialDirectory
// instead of GetSpecialSystemDirectory. The former requires a working XPCOM
// system, which may not be the case for some tests. For querying for the
// location of XPCOM things, we can use it anyway.
nsCOMPtr<nsIFile> ffDir;
nsresult rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(ffDir));
if (NS_SUCCEEDED(rv)) {
nsAutoCString tmpPath;
rv = ffDir->GetNativePath(tmpPath);
if (NS_SUCCEEDED(rv)) {
policy->AddTree(rdonly, tmpPath.get());
}
}
#if defined(MOZ_PROFILE_GENERATE)
AddLLVMProfilePathDirectory(policy.get());
#endif
if (policy->IsEmpty()) {
policy = nullptr;
}
return policy;
}
} // namespace mozilla
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