diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
index 053ee05..af58e8d 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -9,6 +9,7 @@
 #include "core/fpdfapi/parser/cpdf_array.h"
 #include "core/fpdfapi/parser/cpdf_boolean.h"
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_name.h"
 #include "core/fpdfapi/parser/cpdf_number.h"
 #include "core/fpdfapi/parser/cpdf_reference.h"
 #include "core/fpdfapi/parser/cpdf_stream.h"
@@ -162,6 +163,31 @@
   return ret;
 }
 
+bool ValidateDictType(const CPDF_Dictionary* dict, const ByteString& type) {
+  ASSERT(dict);
+  ASSERT(!type.IsEmpty());
+  const CPDF_Name* name_obj = ToName(dict->GetObjectFor("Type"));
+  return name_obj && name_obj->GetString() == type;
+}
+
+bool ValidateDictAllResourcesOfType(const CPDF_Dictionary* dict,
+                                    const ByteString& type) {
+  if (!dict)
+    return false;
+
+  CPDF_DictionaryLocker locker(dict);
+  for (const auto& it : locker) {
+    const CPDF_Dictionary* entry = ToDictionary(it.second.Get()->GetDirect());
+    if (!entry || !ValidateDictType(entry, type))
+      return false;
+  }
+  return true;
+}
+
+bool ValidateFontResourceDict(const CPDF_Dictionary* dict) {
+  return ValidateDictAllResourcesOfType(dict, "Font");
+}
+
 std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj) {
   if (!pObj) {
     buf << " null";
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.h b/core/fpdfapi/parser/fpdf_parser_utility.h
index 29dd246..75f4076 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.h
+++ b/core/fpdfapi/parser/fpdf_parser_utility.h
@@ -55,6 +55,17 @@
 std::vector<float> ReadArrayElementsToVector(const CPDF_Array* pArray,
                                              size_t nCount);
 
+// Returns true if |dict| has a /Type name entry that matches |type|.
+bool ValidateDictType(const CPDF_Dictionary* dict, const ByteString& type);
+
+// Returns true if |dict| is non-null and all entries in |dict| are dictionaries
+// of |type|.
+bool ValidateDictAllResourcesOfType(const CPDF_Dictionary* dict,
+                                    const ByteString& type);
+
+// Shorthand for ValidateDictAllResourcesOfType(dict, "Font").
+bool ValidateFontResourceDict(const CPDF_Dictionary* dict);
+
 std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj);
 
 #endif  // CORE_FPDFAPI_PARSER_FPDF_PARSER_UTILITY_H_
diff --git a/core/fpdfapi/parser/fpdf_parser_utility_unittest.cpp b/core/fpdfapi/parser/fpdf_parser_utility_unittest.cpp
index e3b4e9d..098c3bd 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility_unittest.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility_unittest.cpp
@@ -4,6 +4,14 @@
 
 #include "core/fpdfapi/parser/fpdf_parser_utility.h"
 
+#include "core/fpdfapi/page/cpdf_docpagedata.h"
+#include "core/fpdfapi/page/cpdf_pagemodule.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/cpdf_name.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_string.h"
+#include "core/fpdfapi/render/cpdf_docrenderdata.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(fpdf_parser_utility, PDF_NameDecode) {
@@ -24,3 +32,77 @@
   EXPECT_EQ("#C2", PDF_NameEncode("\xc2"));
   EXPECT_EQ("f#C2#A5", PDF_NameEncode("f\xc2\xa5"));
 }
+
+TEST(fpdf_parser_utility, ValidateDictType) {
+  auto dict = pdfium::MakeRetain<CPDF_Dictionary>();
+
+  // No type.
+  EXPECT_FALSE(ValidateDictType(dict.Get(), "foo"));
+  EXPECT_FALSE(ValidateDictType(dict.Get(), "bar"));
+
+  // Add the wrong object type.
+  dict->SetNewFor<CPDF_String>("Type", L"foo");
+  EXPECT_FALSE(ValidateDictType(dict.Get(), "foo"));
+  EXPECT_FALSE(ValidateDictType(dict.Get(), "bar"));
+
+  // Add the correct object type.
+  dict->SetNewFor<CPDF_Name>("Type", "foo");
+  EXPECT_TRUE(ValidateDictType(dict.Get(), "foo"));
+  EXPECT_FALSE(ValidateDictType(dict.Get(), "bar"));
+}
+
+TEST(fpdf_parser_utility, ValidateDictAllResourcesOfType) {
+  CPDF_PageModule::Create();
+
+  {
+    // Direct dictionary.
+    auto dict = pdfium::MakeRetain<CPDF_Dictionary>();
+
+    // Empty dict is ok.
+    EXPECT_TRUE(ValidateDictAllResourcesOfType(dict.Get(), "foo"));
+    EXPECT_TRUE(ValidateDictAllResourcesOfType(dict.Get(), "bar"));
+
+    // nullptr is not.
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(nullptr, "foo"));
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(nullptr, "bar"));
+
+    // Add two correct dictionary entries and one string entry.
+    CPDF_Dictionary* new_dict = dict->SetNewFor<CPDF_Dictionary>("f1");
+    new_dict->SetNewFor<CPDF_Name>("Type", "foo");
+    new_dict = dict->SetNewFor<CPDF_Dictionary>("f2");
+    new_dict->SetNewFor<CPDF_Name>("Type", "foo");
+    dict->SetNewFor<CPDF_String>("f3", L"foo");
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(dict.Get(), "foo"));
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(dict.Get(), "bar"));
+
+    // Change the string entry to a dictionary, but with the wrong /Type.
+    new_dict = dict->SetNewFor<CPDF_Dictionary>("f3");
+    new_dict->SetNewFor<CPDF_Name>("Type", "bar");
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(dict.Get(), "foo"));
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(dict.Get(), "bar"));
+
+    // Change the /Type to match.
+    new_dict->SetNewFor<CPDF_Name>("Type", "foo");
+    EXPECT_TRUE(ValidateDictAllResourcesOfType(dict.Get(), "foo"));
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(dict.Get(), "bar"));
+  }
+
+  {
+    // Indirect dictionary.
+    auto doc = pdfium::MakeUnique<CPDF_Document>(
+        pdfium::MakeUnique<CPDF_DocRenderData>(),
+        pdfium::MakeUnique<CPDF_DocPageData>());
+
+    auto dict = doc->New<CPDF_Dictionary>();
+
+    // Add a correct dictionary entry.
+    CPDF_Dictionary* new_dict = doc->NewIndirect<CPDF_Dictionary>();
+    new_dict->SetNewFor<CPDF_Name>("Type", "foo");
+    dict->SetNewFor<CPDF_Reference>("f1", doc.get(), new_dict->GetObjNum());
+
+    EXPECT_TRUE(ValidateDictAllResourcesOfType(dict.Get(), "foo"));
+    EXPECT_FALSE(ValidateDictAllResourcesOfType(dict.Get(), "bar"));
+  }
+
+  CPDF_PageModule::Destroy();
+}
diff --git a/core/fpdfdoc/cpdf_formcontrol.cpp b/core/fpdfdoc/cpdf_formcontrol.cpp
index 7e8c190..3b7b9b3 100644
--- a/core/fpdfdoc/cpdf_formcontrol.cpp
+++ b/core/fpdfdoc/cpdf_formcontrol.cpp
@@ -16,6 +16,7 @@
 #include "core/fpdfapi/parser/cpdf_name.h"
 #include "core/fpdfapi/parser/cpdf_stream.h"
 #include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
 #include "core/fpdfdoc/cpdf_interactiveform.h"
 
 namespace {
@@ -220,7 +221,7 @@
   CPDF_Object* pObj = FPDF_GetFieldAttr(m_pWidgetDict.Get(), "DR");
   if (CPDF_Dictionary* pDict = ToDictionary(pObj)) {
     CPDF_Dictionary* pFonts = pDict->GetDictFor("Font");
-    if (pFonts) {
+    if (ValidateFontResourceDict(pFonts)) {
       CPDF_Dictionary* pElement = pFonts->GetDictFor(*csFontNameTag);
       if (pElement) {
         auto* pData = CPDF_DocPageData::FromDocument(m_pForm->GetDocument());
@@ -241,7 +242,7 @@
     return nullptr;
 
   CPDF_Dictionary* pFonts = pDict->GetDictFor("Font");
-  if (!pFonts)
+  if (!ValidateFontResourceDict(pFonts))
     return nullptr;
 
   CPDF_Dictionary* pElement = pFonts->GetDictFor(*csFontNameTag);
diff --git a/core/fpdfdoc/cpdf_formfield.cpp b/core/fpdfdoc/cpdf_formfield.cpp
index 7b1b6ff..9d71bf3 100644
--- a/core/fpdfdoc/cpdf_formfield.cpp
+++ b/core/fpdfdoc/cpdf_formfield.cpp
@@ -22,6 +22,7 @@
 #include "core/fpdfapi/parser/cpdf_number.h"
 #include "core/fpdfapi/parser/cpdf_string.h"
 #include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
 #include "core/fpdfdoc/cpdf_defaultappearance.h"
 #include "core/fpdfdoc/cpdf_formcontrol.h"
 #include "core/fpdfdoc/cpdf_interactiveform.h"
@@ -901,7 +902,7 @@
     return;
 
   CPDF_Dictionary* pFont = pDR->GetDictFor("Font");
-  if (!pFont)
+  if (!ValidateFontResourceDict(pFont))
     return;
 
   CPDF_DefaultAppearance appearance(DA);
diff --git a/core/fpdfdoc/cpdf_interactiveform.cpp b/core/fpdfdoc/cpdf_interactiveform.cpp
index eeaac49..15a5e26 100644
--- a/core/fpdfdoc/cpdf_interactiveform.cpp
+++ b/core/fpdfdoc/cpdf_interactiveform.cpp
@@ -130,7 +130,7 @@
     return nullptr;
 
   CPDF_Dictionary* pFonts = pDR->GetDictFor("Font");
-  if (!pFonts)
+  if (!ValidateFontResourceDict(pFonts))
     return nullptr;
 
   CPDF_Dictionary* pElement = pFonts->GetDictFor(csAlias);
@@ -152,7 +152,7 @@
     return nullptr;
 
   CPDF_Dictionary* pFonts = pDR->GetDictFor("Font");
-  if (!pFonts)
+  if (!ValidateFontResourceDict(pFonts))
     return nullptr;
 
   CPDF_DictionaryLocker locker(pFonts);
@@ -193,7 +193,7 @@
     return false;
 
   CPDF_Dictionary* pFonts = pDR->GetDictFor("Font");
-  if (!pFonts)
+  if (!ValidateFontResourceDict(pFonts))
     return false;
 
   CPDF_DictionaryLocker locker(pFonts);
@@ -227,7 +227,7 @@
     return false;
 
   CPDF_Dictionary* pFonts = pDR->GetDictFor("Font");
-  if (!pFonts)
+  if (!ValidateFontResourceDict(pFonts))
     return false;
 
   if (csFontName.GetLength() > 0)
diff --git a/core/fpdfdoc/cpvt_fontmap.cpp b/core/fpdfdoc/cpvt_fontmap.cpp
index 038a6f4..b21bd0d 100644
--- a/core/fpdfdoc/cpvt_fontmap.cpp
+++ b/core/fpdfdoc/cpvt_fontmap.cpp
@@ -10,6 +10,7 @@
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfapi/parser/cpdf_document.h"
 #include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
 #include "core/fpdfdoc/cpdf_interactiveform.h"
 #include "core/fxcrt/fx_codepage.h"
 #include "third_party/base/logging.h"
@@ -40,7 +41,8 @@
     return nullptr;
 
   CPDF_Dictionary* pFontList = pResDict->GetDictFor("Font");
-  if (pFontList && !pFontList->KeyExist(*sSysFontAlias)) {
+  if (ValidateFontResourceDict(pFontList) &&
+      !pFontList->KeyExist(*sSysFontAlias)) {
     pFontList->SetNewFor<CPDF_Reference>(*sSysFontAlias, pDoc,
                                          pPDFFont->GetFontDict()->GetObjNum());
   }
diff --git a/core/fpdfdoc/cpvt_generateap.cpp b/core/fpdfdoc/cpvt_generateap.cpp
index 0c2143b..b66fc3c 100644
--- a/core/fpdfdoc/cpvt_generateap.cpp
+++ b/core/fpdfdoc/cpvt_generateap.cpp
@@ -945,7 +945,7 @@
     return;
 
   CPDF_Dictionary* pDRFontDict = pDRDict->GetDictFor("Font");
-  if (!pDRFontDict)
+  if (!ValidateFontResourceDict(pDRFontDict))
     return;
 
   CPDF_Dictionary* pFontDict = pDRFontDict->GetDictFor(font_name);
@@ -1069,13 +1069,15 @@
   }
   CPDF_Dictionary* pStreamDict = pNormalStream->GetDict();
   if (pStreamDict) {
-    pStreamDict->SetMatrixFor("Matrix", matrix);
-    pStreamDict->SetRectFor("BBox", rcBBox);
     CPDF_Dictionary* pStreamResList = pStreamDict->GetDictFor("Resources");
     if (pStreamResList) {
       CPDF_Dictionary* pStreamResFontList = pStreamResList->GetDictFor("Font");
-      if (!pStreamResFontList)
+      if (pStreamResFontList) {
+        if (!ValidateFontResourceDict(pStreamResFontList))
+          return;
+      } else {
         pStreamResFontList = pStreamResList->SetNewFor<CPDF_Dictionary>("Font");
+      }
       if (!pStreamResFontList->KeyExist(font_name)) {
         pStreamResFontList->SetNewFor<CPDF_Reference>(font_name, pDoc,
                                                       pFontDict->GetObjNum());
@@ -1083,6 +1085,8 @@
     } else {
       pStreamDict->SetFor("Resources", pFormDict->GetDictFor("DR")->Clone());
     }
+    pStreamDict->SetMatrixFor("Matrix", matrix);
+    pStreamDict->SetRectFor("BBox", rcBBox);
   }
   switch (type) {
     case CPVT_GenerateAP::kTextField: {
@@ -1306,28 +1310,33 @@
     }
   }
 
-  if (pNormalStream) {
-    pNormalStream->SetDataFromStringstreamAndRemoveFilter(&sAppStream);
-    pStreamDict = pNormalStream->GetDict();
-    if (pStreamDict) {
-      pStreamDict->SetMatrixFor("Matrix", matrix);
-      pStreamDict->SetRectFor("BBox", rcBBox);
-      CPDF_Dictionary* pStreamResList = pStreamDict->GetDictFor("Resources");
-      if (pStreamResList) {
-        CPDF_Dictionary* pStreamResFontList =
-            pStreamResList->GetDictFor("Font");
-        if (!pStreamResFontList) {
-          pStreamResFontList =
-              pStreamResList->SetNewFor<CPDF_Dictionary>("Font");
-        }
-        if (!pStreamResFontList->KeyExist(font_name)) {
-          pStreamResFontList->SetNewFor<CPDF_Reference>(font_name, pDoc,
-                                                        pFontDict->GetObjNum());
-        }
-      } else {
-        pStreamDict->SetFor("Resources", pFormDict->GetDictFor("DR")->Clone());
-      }
-    }
+  if (!pNormalStream)
+    return;
+
+  pNormalStream->SetDataFromStringstreamAndRemoveFilter(&sAppStream);
+  pStreamDict = pNormalStream->GetDict();
+  if (!pStreamDict)
+    return;
+
+  pStreamDict->SetMatrixFor("Matrix", matrix);
+  pStreamDict->SetRectFor("BBox", rcBBox);
+  CPDF_Dictionary* pStreamResList = pStreamDict->GetDictFor("Resources");
+  if (!pStreamResList) {
+    pStreamDict->SetFor("Resources", pFormDict->GetDictFor("DR")->Clone());
+    return;
+  }
+
+  CPDF_Dictionary* pStreamResFontList = pStreamResList->GetDictFor("Font");
+  if (pStreamResFontList) {
+    if (!ValidateFontResourceDict(pStreamResFontList))
+      return;
+  } else {
+    pStreamResFontList = pStreamResList->SetNewFor<CPDF_Dictionary>("Font");
+  }
+
+  if (!pStreamResFontList->KeyExist(font_name)) {
+    pStreamResFontList->SetNewFor<CPDF_Reference>(font_name, pDoc,
+                                                  pFontDict->GetObjNum());
   }
 }