File fix-kauth-bypass-CVE-2017-8422.patch of Package kauth
From df875f725293af53399f5146362eb158b4f9216a Mon Sep 17 00:00:00 2001
From: Albert Astals Cid <aacid@kde.org>
Date: Wed, 10 May 2017 10:03:45 +0200
Subject: Verify that whoever is calling us is actually who he says he is
CVE-2017-8422
---
src/AuthBackend.cpp | 5 +++++
src/AuthBackend.h | 7 +++++++
src/backends/dbus/DBusHelperProxy.cpp | 27 +++++++++++++++++++++++++--
src/backends/dbus/DBusHelperProxy.h | 6 +++++-
src/backends/policykit/PolicyKitBackend.cpp | 5 +++++
src/backends/policykit/PolicyKitBackend.h | 1 +
src/backends/polkit-1/Polkit1Backend.cpp | 5 +++++
src/backends/polkit-1/Polkit1Backend.h | 1 +
8 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/src/AuthBackend.cpp b/src/AuthBackend.cpp
index a41d4f1..a847494 100644
--- a/src/AuthBackend.cpp
+++ b/src/AuthBackend.cpp
@@ -54,6 +54,11 @@ void AuthBackend::setCapabilities(AuthBackend::Capabilities capabilities)
d->capabilities = capabilities;
}
+AuthBackend::ExtraCallerIDVerificationMethod AuthBackend::extraCallerIDVerificationMethod() const
+{
+ return NoExtraCallerIDVerificationMethod;
+}
+
bool AuthBackend::actionExists(const QString &action)
{
Q_UNUSED(action);
diff --git a/src/AuthBackend.h b/src/AuthBackend.h
index c67a706..09195ef 100644
--- a/src/AuthBackend.h
+++ b/src/AuthBackend.h
@@ -43,6 +43,12 @@ public:
};
Q_DECLARE_FLAGS(Capabilities, Capability)
+ enum ExtraCallerIDVerificationMethod {
+ NoExtraCallerIDVerificationMethod,
+ VerifyAgainstDBusServiceName,
+ VerifyAgainstDBusServicePid,
+ };
+
AuthBackend();
virtual ~AuthBackend();
virtual void setupAction(const QString &action) = 0;
@@ -50,6 +56,7 @@ public:
virtual Action::AuthStatus authorizeAction(const QString &action) = 0;
virtual Action::AuthStatus actionStatus(const QString &action) = 0;
virtual QByteArray callerID() const = 0;
+ virtual ExtraCallerIDVerificationMethod extraCallerIDVerificationMethod() const;
virtual bool isCallerAuthorized(const QString &action, QByteArray callerID) = 0;
virtual bool actionExists(const QString &action);
diff --git a/src/backends/dbus/DBusHelperProxy.cpp b/src/backends/dbus/DBusHelperProxy.cpp
index 9c5cb96..3c1c108 100644
--- a/src/backends/dbus/DBusHelperProxy.cpp
+++ b/src/backends/dbus/DBusHelperProxy.cpp
@@ -235,6 +235,29 @@ bool DBusHelperProxy::hasToStopAction()
return m_stopRequest;
}
+bool DBusHelperProxy::isCallerAuthorized(const QString &action, const QByteArray &callerID)
+{
+ // Check the caller is really who it says it is
+ switch (BackendsManager::authBackend()->extraCallerIDVerificationMethod()) {
+ case AuthBackend::NoExtraCallerIDVerificationMethod:
+ break;
+
+ case AuthBackend::VerifyAgainstDBusServiceName:
+ if (message().service().toUtf8() != callerID) {
+ return false;
+ }
+ break;
+
+ case AuthBackend::VerifyAgainstDBusServicePid:
+ if (connection().interface()->servicePid(message().service()).value() != callerID.toUInt()) {
+ return false;
+ }
+ break;
+ }
+
+ return BackendsManager::authBackend()->isCallerAuthorized(action, callerID);
+}
+
QByteArray DBusHelperProxy::performAction(const QString &action, const QByteArray &callerID, QByteArray arguments)
{
if (!responder) {
@@ -259,7 +282,7 @@ QByteArray DBusHelperProxy::performAction(const QString &action, const QByteArra
QTimer *timer = responder->property("__KAuth_Helper_Shutdown_Timer").value<QTimer *>();
timer->stop();
- if (BackendsManager::authBackend()->isCallerAuthorized(action, callerID)) {
+ if (isCallerAuthorized(action, callerID)) {
QString slotname = action;
if (slotname.startsWith(m_name + QLatin1Char('.'))) {
slotname = slotname.right(slotname.length() - m_name.length() - 1);
@@ -301,7 +324,7 @@ uint DBusHelperProxy::authorizeAction(const QString &action, const QByteArray &c
QTimer *timer = responder->property("__KAuth_Helper_Shutdown_Timer").value<QTimer *>();
timer->stop();
- if (BackendsManager::authBackend()->isCallerAuthorized(action, callerID)) {
+ if (isCallerAuthorized(action, callerID)) {
retVal = static_cast<uint>(Action::AuthorizedStatus);
} else {
retVal = static_cast<uint>(Action::DeniedStatus);
diff --git a/src/backends/dbus/DBusHelperProxy.h b/src/backends/dbus/DBusHelperProxy.h
index 52b0ac4..82cec5a 100644
--- a/src/backends/dbus/DBusHelperProxy.h
+++ b/src/backends/dbus/DBusHelperProxy.h
@@ -25,12 +25,13 @@
#include "kauthactionreply.h"
#include <QDBusConnection>
+#include <QDBusContext>
#include <QVariant>
namespace KAuth
{
-class DBusHelperProxy : public HelperProxy
+class DBusHelperProxy : public HelperProxy, protected QDBusContext
{
Q_OBJECT
Q_PLUGIN_METADATA(IID "org.kde.DBusHelperProxy")
@@ -79,6 +80,9 @@ Q_SIGNALS:
private Q_SLOTS:
void remoteSignalReceived(int type, const QString &action, QByteArray blob);
+
+private:
+ bool isCallerAuthorized(const QString &action, const QByteArray &callerID);
};
} // namespace Auth
diff --git a/src/backends/policykit/PolicyKitBackend.cpp b/src/backends/policykit/PolicyKitBackend.cpp
index c2b4d42..bf038a8 100644
--- a/src/backends/policykit/PolicyKitBackend.cpp
+++ b/src/backends/policykit/PolicyKitBackend.cpp
@@ -78,6 +78,11 @@ QByteArray PolicyKitBackend::callerID() const
return a;
}
+AuthBackend::ExtraCallerIDVerificationMethod Polkit1Backend::extraCallerIDVerificationMethod() const
+{
+ return VerifyAgainstDBusServicePid;
+}
+
bool PolicyKitBackend::isCallerAuthorized(const QString &action, QByteArray callerID)
{
QDataStream s(&callerID, QIODevice::ReadOnly);
diff --git a/src/backends/policykit/PolicyKitBackend.h b/src/backends/policykit/PolicyKitBackend.h
index eb17a3a..38b0240 100644
--- a/src/backends/policykit/PolicyKitBackend.h
+++ b/src/backends/policykit/PolicyKitBackend.h
@@ -40,6 +40,7 @@ public:
virtual Action::AuthStatus authorizeAction(const QString &);
virtual Action::AuthStatus actionStatus(const QString &);
virtual QByteArray callerID() const;
+ ExtraCallerIDVerificationMethod extraCallerIDVerificationMethod() const Q_DECL_OVERRIDE;
virtual bool isCallerAuthorized(const QString &action, QByteArray callerID);
private Q_SLOTS:
diff --git a/src/backends/polkit-1/Polkit1Backend.cpp b/src/backends/polkit-1/Polkit1Backend.cpp
index 78ee5bb..774588c 100644
--- a/src/backends/polkit-1/Polkit1Backend.cpp
+++ b/src/backends/polkit-1/Polkit1Backend.cpp
@@ -162,6 +162,11 @@ QByteArray Polkit1Backend::callerID() const
return QDBusConnection::systemBus().baseService().toUtf8();
}
+AuthBackend::ExtraCallerIDVerificationMethod Polkit1Backend::extraCallerIDVerificationMethod() const
+{
+ return VerifyAgainstDBusServiceName;
+}
+
bool Polkit1Backend::isCallerAuthorized(const QString &action, QByteArray callerID)
{
PolkitQt1::SystemBusNameSubject subject(QString::fromUtf8(callerID));
diff --git a/src/backends/polkit-1/Polkit1Backend.h b/src/backends/polkit-1/Polkit1Backend.h
index d7d1e3a..2357892 100644
--- a/src/backends/polkit-1/Polkit1Backend.h
+++ b/src/backends/polkit-1/Polkit1Backend.h
@@ -49,6 +49,7 @@ public:
Action::AuthStatus authorizeAction(const QString &) Q_DECL_OVERRIDE;
Action::AuthStatus actionStatus(const QString &) Q_DECL_OVERRIDE;
QByteArray callerID() const Q_DECL_OVERRIDE;
+ ExtraCallerIDVerificationMethod extraCallerIDVerificationMethod() const Q_DECL_OVERRIDE;
bool isCallerAuthorized(const QString &action, QByteArray callerID) Q_DECL_OVERRIDE;
bool actionExists(const QString &action) Q_DECL_OVERRIDE;
--
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