From ab5a5764b2d33ea42f3e458da77494a9c864b35b Mon Sep 17 00:00:00 2001 From: Thiago Macieira Date: Thu, 23 Jul 2020 18:17:19 -0700 Subject: QStandardPaths/Unix: improve the XDG_RUNTIME_DIR creation/detection First, use QT_MKDIR instead of QFileSystemEngine::createDirectory(), as the latter can't create a directory with the right permissions. That would allow an attacker to briefly obtain access to the runtime dir between the mkdir() and chmod() system calls. Second, make sure that if the target already exists that it is a directory and not a symlink (even to a directory). If it is a symlink that belongs to another user, it can be changed to point to another place, which we won't like. And as a bonus, we're printing more information to the user in case something went wrong. Sample outputs: QStandardPaths: runtime directory '/root' is not owned by UID 1000, but a directory permissions 0700 owned by UID 0 GID 0 QStandardPaths: runtime directory '/dev/null' is not a directory, but a character device, socket or FIFO permissions 0666 owned by UID 0 GID 0 QStandardPaths: runtime directory '/etc/passwd' is not a directory, but a regular file permissions 0644 owned by UID 0 GID 0 QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-tjmaciei' QStandardPaths: runtime directory '/tmp/runtime-tjmaciei' is not a directory, but a symbolic link to a directory permissions 0755 owned by UID 1000 GID 100 Change-Id: Iea47e0f8fc8b40378df7fffd16248b663794c613 Reviewed-by: David Faure (cherry picked from commit ad5a65b6a2bfca1658634e380559d14ea1e904a4 plus a lot of others) Reviewed-by: Thiago Macieira --- .../corelib/io/qstandardpaths/qstandardpaths.pro | 2 - .../io/qstandardpaths/tst_qstandardpaths.cpp | 254 +++++++++++++++++---- 2 files changed, 210 insertions(+), 46 deletions(-) (limited to 'tests/auto/corelib/io') diff --git a/tests/auto/corelib/io/qstandardpaths/qstandardpaths.pro b/tests/auto/corelib/io/qstandardpaths/qstandardpaths.pro index 44b1ce8dd8..5c15ad84be 100644 --- a/tests/auto/corelib/io/qstandardpaths/qstandardpaths.pro +++ b/tests/auto/corelib/io/qstandardpaths/qstandardpaths.pro @@ -1,8 +1,6 @@ CONFIG += testcase TARGET = tst_qstandardpaths QT = core testlib -INCLUDEPATH += ../../../../shared/ -HEADERS += ../../../../shared/emulationdetector.h SOURCES = tst_qstandardpaths.cpp TESTDATA += tst_qstandardpaths.cpp qstandardpaths.pro diff --git a/tests/auto/corelib/io/qstandardpaths/tst_qstandardpaths.cpp b/tests/auto/corelib/io/qstandardpaths/tst_qstandardpaths.cpp index 1379c788d1..03eb3ae586 100644 --- a/tests/auto/corelib/io/qstandardpaths/tst_qstandardpaths.cpp +++ b/tests/auto/corelib/io/qstandardpaths/tst_qstandardpaths.cpp @@ -1,6 +1,7 @@ /**************************************************************************** ** -** Copyright (C) 2016 The Qt Company Ltd. +** Copyright (C) 2020 The Qt Company Ltd. +** Copyright (C) 2020 Intel Corporation. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the test suite of the Qt Toolkit. @@ -26,12 +27,11 @@ ** ****************************************************************************/ -#include #include +#include #include -#include #include -#include +#include #include #if defined(Q_OS_WIN) && !defined(Q_OS_WINRT) && !defined(Q_OS_WINCE) # include @@ -40,14 +40,13 @@ #ifdef Q_OS_UNIX #include #include +#include #endif #if defined(Q_OS_UNIX) && !defined(Q_OS_MAC) && !defined(Q_OS_ANDROID) #define Q_XDG_PLATFORM #endif -#include "emulationdetector.h" - // Update this when adding new enum values; update enumNames too static const int MaxStandardLocation = QStandardPaths::AppConfigLocation; @@ -68,6 +67,7 @@ private slots: void testFindExecutable(); void testFindExecutableLinkToDirectory(); void testRuntimeDirectory(); + void testCustomRuntimeDirectory_data(); void testCustomRuntimeDirectory(); void testAllWritableLocations_data(); void testAllWritableLocations(); @@ -460,6 +460,9 @@ void tst_qstandardpaths::testFindExecutableLinkToDirectory() #endif } +using RuntimeDirSetup = QString (*)(QDir &); +Q_DECLARE_METATYPE(RuntimeDirSetup); + void tst_qstandardpaths::testRuntimeDirectory() { #ifdef Q_XDG_PLATFORM @@ -478,6 +481,174 @@ void tst_qstandardpaths::testRuntimeDirectory() #endif } +#ifdef Q_XDG_PLATFORM +static QString fallbackXdgRuntimeDir() +{ + static QString username = [] { + struct passwd *pw = getpwuid(geteuid()); + return QString::fromLocal8Bit(pw->pw_name); + }(); + + // QDir::temp() might change from call to call + return QDir::temp().filePath("runtime-" + username); +} +#endif + +static QString updateRuntimeDir(const QString &path) +{ + qputenv("XDG_RUNTIME_DIR", QFile::encodeName(path)); + return path; +} + +static void clearRuntimeDir() +{ + qunsetenv("XDG_RUNTIME_DIR"); +#ifdef Q_XDG_PLATFORM +#ifndef Q_OS_WASM + QTest::ignoreMessage(QtWarningMsg, + qPrintable("QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '" + + fallbackXdgRuntimeDir() + '\'')); +#endif +#endif +} + +void tst_qstandardpaths::testCustomRuntimeDirectory_data() +{ +#if defined(Q_XDG_PLATFORM) + QTest::addColumn("setup"); + auto addRow = [](const char *name, RuntimeDirSetup f) { + QTest::newRow(name) << f; + }; + + +# if defined(Q_OS_UNIX) + if (::getuid() == 0) + QSKIP("Running this test as root doesn't make sense"); +# endif + + addRow("environment:non-existing", [](QDir &d) { + return updateRuntimeDir(d.filePath("runtime")); + }); + + addRow("environment:existing", [](QDir &d) { + QString p = d.filePath("runtime"); + d.mkdir("runtime"); + QFile::setPermissions(p, QFile::ReadOwner | QFile::WriteOwner | QFile::ExeOwner); + return updateRuntimeDir(p); + }); + + addRow("environment-to-existing-wrong-perm", [](QDir &d) { + QString p = d.filePath("runtime"); + d.mkdir("runtime"); + QFile::setPermissions(p, QFile::ReadOwner | QFile::WriteOwner | QFile::ExeOwner | + QFile::ExeGroup | QFile::ExeOther); + return updateRuntimeDir(p); + }); + + addRow("environment:wrong-owner", [](QDir &) { + QT_STATBUF st; + QT_STAT("/", &st); + + updateRuntimeDir("/"); + QTest::ignoreMessage(QtWarningMsg, + QString("QStandardPaths: runtime directory '/' is not owned by UID " + "%1, but a directory permissions %2 owned by UID %3 GID %4") + .arg(getuid()) + .arg(st.st_mode & 07777, 4, 8, QChar('0')) + .arg(st.st_uid) + .arg(st.st_gid).toLatin1()); + return fallbackXdgRuntimeDir(); + }); + + addRow("environment:file", [](QDir &d) { + QString p = d.filePath("file"); + QFile f(p); + f.open(QIODevice::WriteOnly); + f.setPermissions(QFile::ReadOwner | QFile::WriteOwner); + + updateRuntimeDir(p); + QTest::ignoreMessage(QtWarningMsg, + QString("QStandardPaths: runtime directory '%1' is not a directory, " + "but a regular file permissions 0600 owned by UID %2 GID %3") + .arg(p).arg(getuid()).arg(getgid()).toLatin1()); + return fallbackXdgRuntimeDir(); + }); + + addRow("environment:broken-symlink", [](QDir &d) { + QString p = d.filePath("link"); + QFile::link(d.filePath("this-goes-nowhere"), p); + updateRuntimeDir(p); + QTest::ignoreMessage(QtWarningMsg, + QString("QStandardPaths: runtime directory '%1' is not a directory, " + "but a broken symlink") + .arg(p).toLatin1()); + return fallbackXdgRuntimeDir(); + }); + + addRow("environment:symlink-to-dir", [](QDir &d) { + QString p = d.filePath("link"); + d.mkdir("dir"); + QFile::link(d.filePath("dir"), p); + QFile::setPermissions(p, QFile::ReadOwner | QFile::WriteOwner | QFile::ExeOwner); + updateRuntimeDir(p); + QTest::ignoreMessage(QtWarningMsg, + QString("QStandardPaths: runtime directory '%1' is not a directory, " + "but a symbolic link to a directory permissions 0700 owned by UID %2 GID %3") + .arg(p).arg(getuid()).arg(getgid()).toLatin1()); + return fallbackXdgRuntimeDir(); + }); + + addRow("no-environment:non-existing", [](QDir &) { + clearRuntimeDir(); + return fallbackXdgRuntimeDir(); + }); + + addRow("no-environment:existing", [](QDir &d) { + clearRuntimeDir(); + QString p = fallbackXdgRuntimeDir(); + d.mkdir(p); // probably has wrong permissions + return p; + }); + + addRow("no-environment:fallback-is-file", [](QDir &) { + QString p = fallbackXdgRuntimeDir(); + QFile f(p); + f.open(QIODevice::WriteOnly); + f.setPermissions(QFile::ReadOwner | QFile::WriteOwner); + + clearRuntimeDir(); + QTest::ignoreMessage(QtWarningMsg, + QString("QStandardPaths: runtime directory '%1' is not a directory, " + "but a regular file permissions 0600 owned by UID %2 GID %3") + .arg(p).arg(getuid()).arg(getgid()).toLatin1()); + return QString(); + }); + + addRow("environment-and-fallback-are-files", [](QDir &d) { + QString p = d.filePath("file1"); + QFile f(p); + f.open(QIODevice::WriteOnly); + f.setPermissions(QFile::ReadOwner | QFile::WriteOwner | QFile::ReadGroup); + updateRuntimeDir(p); + QTest::ignoreMessage(QtWarningMsg, + QString("QStandardPaths: runtime directory '%1' is not a directory, " + "but a regular file permissions 0640 owned by UID %2 GID %3") + .arg(p).arg(getuid()).arg(getgid()).toLatin1()); + + f.close(); + f.setFileName(fallbackXdgRuntimeDir()); + f.open(QIODevice::WriteOnly); + f.setPermissions(QFile::ReadOwner | QFile::WriteOwner | QFile::ReadGroup); + QTest::ignoreMessage(QtWarningMsg, + QString("QStandardPaths: runtime directory '%1' is not a directory, " + "but a regular file permissions 0640 owned by UID %2 GID %3") + .arg(f.fileName()).arg(getuid()).arg(getgid()).toLatin1()); + + return QString(); + }); +#endif +} + void tst_qstandardpaths::testCustomRuntimeDirectory() { #if defined(Q_OS_UNIX) @@ -488,47 +659,38 @@ void tst_qstandardpaths::testCustomRuntimeDirectory() #ifdef Q_XDG_PLATFORM struct EnvVarRestorer { - EnvVarRestorer() : origRuntimeDir(qgetenv("XDG_RUNTIME_DIR")) {} - ~EnvVarRestorer() { qputenv("XDG_RUNTIME_DIR", origRuntimeDir.constData()); } - const QByteArray origRuntimeDir; + ~EnvVarRestorer() + { + qputenv("XDG_RUNTIME_DIR", origRuntimeDir); + qputenv("TMPDIR", origTempDir); + } + const QByteArray origRuntimeDir = qgetenv("XDG_RUNTIME_DIR"); + const QByteArray origTempDir = qgetenv("TMPDIR"); }; EnvVarRestorer restorer; - // When $XDG_RUNTIME_DIR points to a directory with wrong ownership, QStandardPaths should warn - QByteArray rootOwnedFileName = "/tmp"; - if (EmulationDetector::isRunningArmOnX86()) { - // Directory "tmp" under toolchain sysroot is detected by qemu and has same uid as current user. - // Try /opt instead, it might not be located in the sysroot. - QFileInfo rootOwnedFile = QFileInfo(QString::fromLatin1(rootOwnedFileName)); - if (rootOwnedFile.ownerId() == ::geteuid()) { - rootOwnedFileName = "/opt"; - } - } - qputenv("XDG_RUNTIME_DIR", QFile::encodeName(rootOwnedFileName)); + // set up the environment to point to a place we control + QTemporaryDir tempDir; + QVERIFY2(tempDir.isValid(), qPrintable(tempDir.errorString())); - // It's very unlikely that /tmp is 0600 or that we can chmod it - // The call below outputs - // "QStandardPaths: wrong ownership on runtime directory /tmp, 0 instead of $UID" - // but we can't reliably expect that it's owned by uid 0, I think. - const uid_t uid = geteuid(); - QTest::ignoreMessage(QtWarningMsg, - qPrintable(QString::fromLatin1("QStandardPaths: wrong ownership on runtime directory " + rootOwnedFileName + ", 0 instead of %1").arg(uid))); - const QString runtimeDir = QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation); - QVERIFY2(runtimeDir.isEmpty(), qPrintable(runtimeDir)); - - // When $XDG_RUNTIME_DIR points to a non-existing directory, QStandardPaths should warn (QTBUG-48771) - qputenv("XDG_RUNTIME_DIR", "does_not_exist"); - QTest::ignoreMessage(QtWarningMsg, "QStandardPaths: XDG_RUNTIME_DIR points to non-existing path 'does_not_exist', please create it with 0700 permissions."); - const QString nonExistingRuntimeDir = QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation); - QVERIFY2(nonExistingRuntimeDir.isEmpty(), qPrintable(nonExistingRuntimeDir)); - - // When $XDG_RUNTIME_DIR points to a file, QStandardPaths should warn - const QString file = QFINDTESTDATA("tst_qstandardpaths.cpp"); - QVERIFY(!file.isEmpty()); - qputenv("XDG_RUNTIME_DIR", QFile::encodeName(file)); - QTest::ignoreMessage(QtWarningMsg, qPrintable(QString::fromLatin1("QStandardPaths: XDG_RUNTIME_DIR points to '%1' which is not a directory").arg(file))); - const QString noRuntimeDir = QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation); - QVERIFY2(noRuntimeDir.isEmpty(), qPrintable(file)); + QDir d(tempDir.path()); + qputenv("TMPDIR", QFile::encodeName(tempDir.path())); + + QFETCH(RuntimeDirSetup, setup); + QString expected = setup(d); + + QString runtimeDir = QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation); + QCOMPARE(runtimeDir, expected); + + if (!runtimeDir.isEmpty()) { + QFileInfo runtimeInfo(runtimeDir); + QVERIFY(runtimeInfo.isDir()); + QVERIFY(!runtimeInfo.isSymLink()); + auto expectedPerms = QFile::ReadOwner | QFile::WriteOwner | QFile::ExeOwner + | QFile::ReadUser | QFile::WriteUser | QFile::ExeUser; + QCOMPARE(QString::number(runtimeInfo.permissions(), 16), + QString::number(expectedPerms, 16)); + } #endif } @@ -566,7 +728,8 @@ void tst_qstandardpaths::testAllWritableLocations() void tst_qstandardpaths::testCleanPath() { - const QRegExp filter(QStringLiteral("\\\\")); +#if QT_CONFIG(regularexpression) + const QRegularExpression filter(QStringLiteral("\\\\")); QVERIFY(filter.isValid()); for (int i = 0; i <= QStandardPaths::GenericCacheLocation; ++i) { const QStringList paths = QStandardPaths::standardLocations(QStandardPaths::StandardLocation(i)); @@ -574,6 +737,9 @@ void tst_qstandardpaths::testCleanPath() qPrintable(QString::fromLatin1("Backslash found in %1 %2") .arg(i).arg(paths.join(QLatin1Char(','))))); } +#else + QSKIP("regularexpression feature disabled"); +#endif } void tst_qstandardpaths::testXdgPathCleanup() -- cgit v1.2.3