From ca8c9933758cb85b2a8e8cc116861a077558d696 Mon Sep 17 00:00:00 2001
From: Jean-Michel Trivi <jmtrivi@google.com>
Date: Mon, 10 Sep 2018 15:50:19 -0700
Subject: Prevent out of bounds accesses in lppTransposer()

Check validity of pSettings->noOfPatches to prevent out of bounds
  access in lppTransposer(), which can also cause memSize to be
  negative.

Bug: 112160868
Test: see poc in bug
Change-Id: I789030b116da7f8ea261001b43ef6c677dd58a3d
Merged-In: I6a2161865d9cb9b51dc37c09d6e3a4a8e5d11f86
(cherry picked from commit 56ef80d7fec1fd9e201262348a96b8660558105a)
---
 Android.mk                 |  2 ++
 libSBRdec/src/lpp_tran.cpp | 37 ++++++++++++++++++++++++-------------
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/Android.mk b/Android.mk
index cfd5113..29331fb 100644
--- a/Android.mk
+++ b/Android.mk
@@ -41,6 +41,8 @@ LOCAL_SRC_FILES := \
 
 LOCAL_CFLAGS += -Wno-sequence-point -Wno-extra
 
+LOCAL_SHARED_LIBRARIES := liblog
+
 LOCAL_C_INCLUDES := \
         $(LOCAL_PATH)/libAACdec/include \
         $(LOCAL_PATH)/libAACenc/include \
diff --git a/libSBRdec/src/lpp_tran.cpp b/libSBRdec/src/lpp_tran.cpp
index e30dd1e..c3f62fb 100644
--- a/libSBRdec/src/lpp_tran.cpp
+++ b/libSBRdec/src/lpp_tran.cpp
@@ -96,6 +96,10 @@ amm-info@iis.fraunhofer.de
   \sa lppTransposer(), main_audio.cpp, sbr_scale.h, \ref documentationOverview
 */
 
+#ifdef __ANDROID__
+#include "log/log.h"
+#endif
+
 #include "lpp_tran.h"
 
 #include "sbr_ram.h"
@@ -256,7 +260,6 @@ void lppTransposer (HANDLE_SBR_LPP_TRANS hLppTrans,    /*!< Handle of lpp transp
   int ovLowBandShift;
   int lowBandShift;
 /*  int ovHighBandShift;*/
-  int targetStopBand;
 
 
   alphai[0] = FL2FXCONST_SGL(0.0f);
@@ -273,24 +276,32 @@ void lppTransposer (HANDLE_SBR_LPP_TRANS hLppTrans,    /*!< Handle of lpp transp
 
   autoCorrLength = pSettings->nCols + pSettings->overlap;
 
-  /* Set upper subbands to zero:
-     This is required in case that the patches do not cover the complete highband
-     (because the last patch would be too short).
-     Possible optimization: Clearing bands up to usb would be sufficient here. */
-  targetStopBand = patchParam[pSettings->noOfPatches-1].targetStartBand
-                 + patchParam[pSettings->noOfPatches-1].numBandsInPatch;
+  if (pSettings->noOfPatches > 0) {
+    /* Set upper subbands to zero:
+       This is required in case that the patches do not cover the complete highband
+       (because the last patch would be too short).
+       Possible optimization: Clearing bands up to usb would be sufficient here. */
+    int targetStopBand = patchParam[pSettings->noOfPatches-1].targetStartBand
+                   + patchParam[pSettings->noOfPatches-1].numBandsInPatch;
 
-  int memSize = ((64) - targetStopBand) * sizeof(FIXP_DBL);
+    int memSize = ((64) - targetStopBand) * sizeof(FIXP_DBL);
 
-  if (!useLP) {
+    if (!useLP) {
+      for (i = startSample; i < stopSampleClear; i++) {
+        FDKmemclear(&qmfBufferReal[i][targetStopBand], memSize);
+        FDKmemclear(&qmfBufferImag[i][targetStopBand], memSize);
+      }
+    } else
     for (i = startSample; i < stopSampleClear; i++) {
       FDKmemclear(&qmfBufferReal[i][targetStopBand], memSize);
-      FDKmemclear(&qmfBufferImag[i][targetStopBand], memSize);
     }
-  } else
-  for (i = startSample; i < stopSampleClear; i++) {
-    FDKmemclear(&qmfBufferReal[i][targetStopBand], memSize);
   }
+#ifdef __ANDROID__
+  else {
+    // Safetynet logging
+    android_errorWriteLog(0x534e4554, "112160868");
+  }
+#endif
 
   /* init bwIndex for each patch */
   FDKmemclear(bwIndex, MAX_NUM_PATCHES*sizeof(INT));
-- 
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