Avoid nullptr access in sycc422_to_rgb and sycc420_to_rgb

core/fxcodec/codec/fx_codec_jpx_opj.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 229 matching lines @@
   OPJ_UINT32 maxw = img->comps[0].w;
   OPJ_UINT32 maxh = img->comps[0].h;
   FX_SAFE_SIZE_T max_size = maxw;
   max_size *= maxh;
   if (!max_size.IsValid())
     return;
 
   const int* y = img->comps[0].data;
   const int* cb = img->comps[1].data;
   const int* cr = img->comps[2].data;
+  if (!y || !cb || !cr)
+    return;
+
   int *d0, *d1, *d2, *r, *g, *b;
   d0 = r = FX_Alloc(int, max_size.ValueOrDie());
   d1 = g = FX_Alloc(int, max_size.ValueOrDie());
   d2 = b = FX_Alloc(int, max_size.ValueOrDie());
   for (uint32_t i = 0; i < maxh; ++i) {
     OPJ_UINT32 j;
     for (j = 0; j < (maxw & ~static_cast<OPJ_UINT32>(1)); j += 2) {
       sycc_to_rgb(offset, upb, *y, *cb, *cr, r, g, b);
       ++y;
       ++r;
@@ skipping 57 matching lines @@
     return;
   int* r = FX_Alloc(int, safeSize.ValueOrDie());
   int* g = FX_Alloc(int, safeSize.ValueOrDie());
   int* b = FX_Alloc(int, safeSize.ValueOrDie());
   int* d0 = r;
   int* d1 = g;
   int* d2 = b;
   const int* y = img->comps[0].data;
   const int* cb = img->comps[1].data;
   const int* cr = img->comps[2].data;
+  if (!y || !cb || !cr)
+    return;
+
   const int* ny = nullptr;
   int* nr = nullptr;
   int* ng = nullptr;
   int* nb = nullptr;
   OPJ_UINT32 i = 0;
   OPJ_UINT32 j = 0;
   for (i = 0; i < (yh & ~(OPJ_UINT32)1); i += 2) {
     ny = y + yw;
     nr = r + yw;
     ng = g + yw;
@@ skipping 566 matching lines @@
 bool CCodec_JpxModule::Decode(CJPX_Decoder* pDecoder,
                               uint8_t* dest_data,
                               int pitch,
                               const std::vector<uint8_t>& offsets) {
   return pDecoder->Decode(dest_data, pitch, offsets);
 }
 
 void CCodec_JpxModule::DestroyDecoder(CJPX_Decoder* pDecoder) {
   delete pDecoder;
 }