Check m_nComponents when using JBIG2Decode

core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp

Index: core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
index f3a1996ab4aa60278db44e9ea2719ece3467135b..cd81b2edebd1f04eab5174571f2d6bbfbf16d102 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
@@ -317,11 +317,9 @@ int	CPDF_DIBSource::StartLoadDIBSource(CPDF_Document* pDoc, const CPDF_Stream* p
     if (!LoadColorInfo(m_pStream->GetObjNum() != 0 ? NULL : pFormResources, pPageResources)) {
         return 0;
     }
-
     if (m_bpc == 0 || m_nComponents == 0) {
         return 0;
     }
-
     FX_SAFE_DWORD src_pitch = m_bpc;
     src_pitch *= m_nComponents;
     src_pitch *= m_Width;
@@ -331,16 +329,12 @@ int	CPDF_DIBSource::StartLoadDIBSource(CPDF_Document* pDoc, const CPDF_Stream* p
     if (!src_pitch.IsValid()) {
         return 0;
     }
-
     m_pStreamAcc = FX_NEW CPDF_StreamAcc;
     m_pStreamAcc->LoadAllData(pStream, FALSE, src_pitch.ValueOrDie(), TRUE);
     if (m_pStreamAcc->GetSize() == 0 || m_pStreamAcc->GetData() == NULL) {
         return 0;
     }
     const CFX_ByteString& decoder = m_pStreamAcc->GetImageDecoder();
-    if (!decoder.IsEmpty() && decoder == FX_BSTRC("CCITTFaxDecode")) {
-        m_bpc = 1;
-    }
     int ret = CreateDecoder();
     if (ret != 1) {
         if (!ret) {
@@ -450,8 +444,6 @@ int	CPDF_DIBSource::ContinueLoadDIBSource(IFX_Pause* pPause)
 }
 FX_BOOL CPDF_DIBSource::LoadColorInfo(CPDF_Dictionary* pFormResources, CPDF_Dictionary* pPageResources)
 {
-    m_bpc_orig = m_pDict->GetInteger(FX_BSTRC("BitsPerComponent"));
-    ValidateBpc();
     if (m_pDict->GetInteger("ImageMask")) {
         m_bImageMask = TRUE;
     }
@@ -505,6 +497,8 @@ FX_BOOL CPDF_DIBSource::LoadColorInfo(CPDF_Dictionary* pFormResources, CPDF_Dict
             m_nComponents = 4;
         }
     }
+    m_bpc_orig = m_pDict->GetInteger(FX_BSTRC("BitsPerComponent"));

[Tom Sepez, 2014/09/02 22:11:54]

Maybe this assignment goes as the first line of ValidateDictParams().

[Bo Xu, 2014/09/02 22:27:13]

Done.

+    ValidateDictParam();
     m_pCompData = FX_Alloc(DIB_COMP_DATA, m_nComponents);
     if (m_bpc == 0) {
         return TRUE;
@@ -915,7 +909,7 @@ void CPDF_DIBSource::LoadPalette()
         }
     }
 }
-void CPDF_DIBSource::ValidateBpc()
+void CPDF_DIBSource::ValidateDictParam()
 {
     m_bpc = m_bpc_orig;
 	CPDF_Object * pFilter = m_pDict ? m_pDict->GetElementValue(FX_BSTRC("Filter")) : NULL;

[Tom Sepez, 2014/09/02 22:11:54]

nit: we de-ref'd m_pDict just before calling this method, hence it cant be NULL.

[Bo Xu, 2014/09/02 22:27:13]

Now check m_pDict in CPDF_DIBSource::Load to make sure m_pDict is not NULL here
and in LoadColorInfo()

@@ -924,6 +918,7 @@ void CPDF_DIBSource::ValidateBpc()
             CFX_ByteString filter = pFilter->GetString();
             if (filter == FX_BSTRC("CCITTFaxDecode") || filter == FX_BSTRC("JBIG2Decode")) {
                 m_bpc = 1;
+                m_nComponents = 1;
             }
             if (filter == FX_BSTRC("RunLengthDecode") || filter == FX_BSTRC("DCTDecode")) {
                 m_bpc = 8;
@@ -933,6 +928,7 @@ void CPDF_DIBSource::ValidateBpc()
             if (pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("CCITTFacDecode") ||
                     pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("JBIG2Decode")) {
                 m_bpc = 1;
+                m_nComponents = 1;
             }
             if (pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("RunLengthDecode") ||
                     pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("DCTDecode")) {