commit c60c36916666ead0ad9c599b82a86708a91eb767
author François Gaffie <francois.gaffie@renault.com> Fri Aug 09 15:41:24 2019 +0200
committer Eric Laurent <elaurent@google.com> Wed Oct 09 15:05:58 2019 -0700
tree 520eb229b4f475fdc7134d594b3fb9b47f72330c
parent bc5c7de7048dfe5ca33652533582328775bd4169

audiopolicy: engineconfigurable: fix potential segfault if no default device

If no default device is available from configuration.xml, and if
the engine fallbacks on it anyway, it tries to get its type without checking
the pointer validity.

This CL fix the potential segfault and assert with explicit error message.

Test: build

Change-Id: Icf8d7f5ef998dad6f4033d934b48d408030c7e17
Signed-off-by: François Gaffie <francois.gaffie@renault.com>

services/audiopolicy/engineconfigurable/src/Engine.cpp

diff --git a/services/audiopolicy/engineconfigurable/src/Engine.cpp b/services/audiopolicy/engineconfigurable/src/Engine.cpp
index c37efca..3987294 100644
--- a/services/audiopolicy/engineconfigurable/src/Engine.cpp
+++ b/services/audiopolicy/engineconfigurable/src/Engine.cpp
@@ -33,6 +33,8 @@
 #include <AudioIODescriptorInterface.h>
 #include <ParameterManagerWrapper.h>
 
+#include <media/TypeConverter.h>
+
 using std::string;
 using std::map;
 
@@ -244,9 +246,9 @@
     }
     if (devices == AUDIO_DEVICE_NONE ||
             (devices & availableOutputDevicesType) == AUDIO_DEVICE_NONE) {
-        devices = getApmObserver()->getDefaultOutputDevice()->type();
-        ALOGE_IF(devices == AUDIO_DEVICE_NONE, "%s: no valid default device defined", __FUNCTION__);
-        return DeviceVector(getApmObserver()->getDefaultOutputDevice());
+        auto defaultDevice = getApmObserver()->getDefaultOutputDevice();
+        ALOG_ASSERT(defaultDevice != nullptr, "no valid default device defined");
+        return DeviceVector(defaultDevice);
     }
     if (/*device_distinguishes_on_address(devices)*/ devices == AUDIO_DEVICE_OUT_BUS) {
         // We do expect only one device for these types of devices
@@ -254,6 +256,14 @@
         // If this criterion is not wished, need to ensure this device is available
         const String8 address(productStrategies.getDeviceAddressForProductStrategy(ps).c_str());
         ALOGV("%s:device 0x%x %s %d", __FUNCTION__, devices, address.c_str(), ps);
+        auto busDevice = availableOutputDevices.getDevice(devices, address, AUDIO_FORMAT_DEFAULT);
+        if (busDevice == nullptr) {
+            ALOGE("%s:unavailable device 0x%x %s, fallback on default", __func__, devices,
+                  address.c_str());
+            auto defaultDevice = getApmObserver()->getDefaultOutputDevice();
+            ALOG_ASSERT(defaultDevice != nullptr, "Default Output Device NOT available");
+            return DeviceVector(defaultDevice);
+        }
         return DeviceVector(availableOutputDevices.getDevice(devices,
                                                              address,
                                                              AUDIO_FORMAT_DEFAULT));