commit d338dfe5830df0960b7b16b7191cb42bd2115996
author Ryan Mitchell <rtmitchell@google.com> Sat Feb 23 15:33:08 2019 +0800
committer Ryan Mitchell <rtmitchell@google.com> Thu May 28 14:03:27 2020 -0700
tree 1ecce02639f04419ecdfd43a5c86f05bbaabbffb
parent 57e977a5859ff24f5ff909046dccde5bce341f6d

Avoid Asset::LoadImpl crash when getBuffer is null

If for some reason Asset::getBuffer returns a null pointer, error out
instead of dereferencing the null pointer.

Bug: 125943266
Bug: 154461471

Test: boots
Change-Id: I957be4f9b8c49c2a6829e8b82fae0ae8d8d7639e

libs/androidfw/ApkAssets.cpp

diff --git a/libs/androidfw/ApkAssets.cpp b/libs/androidfw/ApkAssets.cpp
old mode 100644
new mode 100755
index 05f4d6b..e15b42d
--- a/libs/androidfw/ApkAssets.cpp
+++ b/libs/androidfw/ApkAssets.cpp
@@ -496,6 +496,11 @@
   const StringPiece data(
       reinterpret_cast<const char*>(loaded_apk->resources_asset_->getBuffer(true /*wordAligned*/)),
       loaded_apk->resources_asset_->getLength());
+  if (data.data() == nullptr || data.empty()) {
+    LOG(ERROR) << "Failed to read '" << kResourcesArsc << "' data in APK '" << path << "'.";
+    return {};
+  }
+
   loaded_apk->loaded_arsc_ = LoadedArsc::Load(data, loaded_apk->loaded_idmap_.get(),
                                               property_flags);
   if (!loaded_apk->loaded_arsc_) {
@@ -523,9 +528,14 @@
   const StringPiece data(
       reinterpret_cast<const char*>(loaded_apk->resources_asset_->getBuffer(true /*wordAligned*/)),
       loaded_apk->resources_asset_->getLength());
+  if (data.data() == nullptr || data.empty()) {
+    LOG(ERROR) << "Failed to read resources table data in '" << path << "'.";
+    return {};
+  }
+
   loaded_apk->loaded_arsc_ = LoadedArsc::Load(data, nullptr, property_flags);
   if (loaded_apk->loaded_arsc_ == nullptr) {
-    LOG(ERROR) << "Failed to load '" << kResourcesArsc << path;
+    LOG(ERROR) << "Failed to read resources table in '" << path << "'.";
     return {};
   }