Fix for Heap-buffer-overflow in Codec__decodeXAACStream (#85)

These changes fix the Heap-buffer-overflow in Codec__decodeXAACStream runtime error
caused due to unsupported frame length type configuration for LATM streams.

Bug: ossFuzz:67767
Test: poc in bug

decoder/ixheaacd_headerdecode.c

@@ -1127,19 +1127,12 @@ WORD32 ixheaacd_aac_headerdecode(
             ixheaacd_latm_header_decode(aac_state_struct, &it_bit_buff,
                                         bytes_consumed, pstr_samp_rate_info);
         if (result != 0) {
-          if ((result ==
-               (WORD32)
-                   IA_XHEAAC_DEC_EXE_NONFATAL_INSUFFICIENT_INPUT_BYTES) ||
-              (result ==
-               (WORD32)IA_XHEAAC_DEC_INIT_FATAL_STREAM_CHAN_GT_MAX)) {
+          if ((result == (WORD32)IA_XHEAAC_DEC_EXE_NONFATAL_INSUFFICIENT_INPUT_BYTES) ||
+              (result < 0)) {
             bytes_taken += *bytes_consumed;
             *bytes_consumed = bytes_taken;
             return result;
-          } else if (result == -1)
-            return -1;
-          else if (result == (WORD32)IA_FATAL_ERROR)
-            return IA_FATAL_ERROR;
-          else
+          } else
             bytes_taken += *bytes_consumed - 1;
           continue;
         }

decoder/ixheaacd_latmdemux.c

@@ -253,6 +253,8 @@ IA_ERRORCODE ixheaacd_latm_stream_mux_config(
             }
             break;
 
+          case 1:
+            latm_element->frame_length = ixheaacd_read_bits_buf(it_bit_buff, 9);
           default:
             return IA_XHEAAC_DEC_EXE_FATAL_INVALID_LOAS_HEADER;
         }

fuzzer/xaac_dec_fuzzer.cpp

@@ -52,6 +52,13 @@
 
 #define MAX_MEM_ALLOCS 100
 
+#define IA_MAX_OUTPUT_PCM_SIZE (3)
+#define IA_MAX_USAC_CH (2)
+#define IA_MAX_OUT_SAMPLES_PER_FRAME (4096)
+
+#define IA_DRC_DEC_IN_OUT_BUF_SIZE \
+  (IA_MAX_USAC_CH * IA_MAX_OUT_SAMPLES_PER_FRAME * IA_MAX_OUTPUT_PCM_SIZE)
+
 class Codec {
  public:
   IA_ERRORCODE initDecoder(const uint8_t* data, size_t size, bool isADTS);
@@ -396,10 +403,7 @@ IA_ERRORCODE Codec::initMPEGDDDrc() {
                               pv_alloc_ptr);
   }
 
-  WORD32 ui_size;
-  ui_size = 8192 * 2;
-
-  mDrcInBuf = (int8_t*)malloc(ui_size);
+  mDrcInBuf = (int8_t*)malloc(IA_DRC_DEC_IN_OUT_BUF_SIZE);
   if (mDrcInBuf == nullptr) {
     return IA_FATAL_ERROR;
   }
@@ -408,7 +412,7 @@ IA_ERRORCODE Codec::initMPEGDDDrc() {
   err_code =
       ia_drc_dec_api(mMpegDDrcHandle, IA_API_CMD_SET_MEM_PTR, 2, mDrcInBuf);
 
-  mDrcOutBuf = (int8_t*)malloc(ui_size);
+  mDrcOutBuf = (int8_t*)malloc(IA_DRC_DEC_IN_OUT_BUF_SIZE);
   if (mDrcOutBuf == nullptr) {
     return IA_FATAL_ERROR;
   }