From 1ae0764e01ac0ad15cc16395fc36809343755823 Mon Sep 17 00:00:00 2001
From: Dan Albert <danalbert@google.com>
Date: Thu, 9 Apr 2015 14:11:18 -0700
Subject: [PATCH] Prevent unaligned read in libziparchive.

Change-Id: I4afc3729a1b2c06a6621cb8c9742fc94b5a665f5
---
 libziparchive/Android.mk     | 10 +++++-----
 libziparchive/zip_archive.cc | 33 ++++++++++++++++-----------------
 2 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/libziparchive/Android.mk b/libziparchive/Android.mk
index 0d31001aa..a3087eed7 100644
--- a/libziparchive/Android.mk
+++ b/libziparchive/Android.mk
@@ -21,7 +21,7 @@ include $(CLEAR_VARS)
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_SRC_FILES := ${source_files}
 LOCAL_STATIC_LIBRARIES := libz
-LOCAL_SHARED_LIBRARIES := libutils
+LOCAL_SHARED_LIBRARIES := libutils libbase
 LOCAL_MODULE:= libziparchive
 LOCAL_CFLAGS := -Werror -Wall
 LOCAL_CPPFLAGS := -Wold-style-cast
@@ -30,7 +30,7 @@ include $(BUILD_STATIC_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_SRC_FILES := ${source_files}
-LOCAL_STATIC_LIBRARIES := libz libutils
+LOCAL_STATIC_LIBRARIES := libz libutils libbase
 LOCAL_MODULE:= libziparchive-host
 LOCAL_CFLAGS := -Werror
 ifneq ($(strip $(USE_MINGW)),)
@@ -43,7 +43,7 @@ include $(CLEAR_VARS)
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_SRC_FILES := ${source_files}
 LOCAL_STATIC_LIBRARIES := libz libutils
-LOCAL_SHARED_LIBRARIES := liblog
+LOCAL_SHARED_LIBRARIES := liblog libbase
 LOCAL_MODULE:= libziparchive-host
 LOCAL_CFLAGS := -Werror
 LOCAL_MULTILIB := both
@@ -55,7 +55,7 @@ LOCAL_MODULE := ziparchive-tests
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_CFLAGS := -Werror
 LOCAL_SRC_FILES := zip_archive_test.cc entry_name_utils_test.cc
-LOCAL_SHARED_LIBRARIES := liblog
+LOCAL_SHARED_LIBRARIES := liblog libbase
 LOCAL_STATIC_LIBRARIES := libziparchive libz libutils
 include $(BUILD_NATIVE_TEST)
 
@@ -66,7 +66,7 @@ LOCAL_CFLAGS += \
     -Werror \
     -Wno-unnamed-type-template-args
 LOCAL_SRC_FILES := zip_archive_test.cc entry_name_utils_test.cc
-LOCAL_SHARED_LIBRARIES := libziparchive-host liblog
+LOCAL_SHARED_LIBRARIES := libziparchive-host liblog libbase
 LOCAL_STATIC_LIBRARIES := \
     libz \
     libutils
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index 58285f130..57c46a3c3 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -18,27 +18,29 @@
  * Read-only access to Zip archives, with minimal heap allocation.
  */
 
-#include <memory>
-#include <vector>
-
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <limits.h>
-#include <log/log.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <utils/Compat.h>
-#include <utils/FileMap.h>
-#include <zlib.h>
 
-#include <JNIHelp.h>  // TEMP_FAILURE_RETRY may or may not be in unistd
+#include <memory>
+#include <vector>
+
+#include "base/macros.h"  // TEMP_FAILURE_RETRY may or may not be in unistd
+#include "base/memory.h"
+#include "log/log.h"
+#include "utils/Compat.h"
+#include "utils/FileMap.h"
+#include "zlib.h"
 
 #include "entry_name_utils-inl.h"
 #include "ziparchive/zip_archive.h"
 
+using android::base::get_unaligned;
 
 // This is for windows. If we don't open a file in binary mode, weird
 // things will happen.
@@ -46,11 +48,6 @@
 #define O_BINARY 0
 #endif
 
-#define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
-    TypeName(); \
-    TypeName(const TypeName&); \
-    void operator=(const TypeName&)
-
 // The "end of central directory" (EOCD) record. Each archive
 // contains exactly once such record which appears at the end of
 // the archive. It contains archive wide information like the
@@ -462,10 +459,12 @@ static int32_t MapCentralDirectory0(int fd, const char* debug_file_name,
    */
   int i = read_amount - sizeof(EocdRecord);
   for (; i >= 0; i--) {
-    if (scan_buffer[i] == 0x50 &&
-        ((*reinterpret_cast<uint32_t*>(&scan_buffer[i])) == EocdRecord::kSignature)) {
-      ALOGV("+++ Found EOCD at buf+%d", i);
-      break;
+    if (scan_buffer[i] == 0x50) {
+      uint32_t* sig_addr = reinterpret_cast<uint32_t*>(&scan_buffer[i]);
+      if (get_unaligned<uint32_t>(sig_addr) == EocdRecord::kSignature) {
+        ALOGV("+++ Found EOCD at buf+%d", i);
+        break;
+      }
     }
   }
   if (i < 0) {