SetPos to at most the file length to avoid overflows

This CL prevents arbitrary position setting which may cause integer overflows.
In the bug in question, the PDF says the xrefs are located in a huge position.
This then causes problems when calling CPDF_SyntaxParser methods.

Bug: chromium:603545
Change-Id: I5f94c38f46a0217e9f12f1bf8b2f3bee3b03cb35
Reviewed-on: https://pdfium-review.googlesource.com/4813
Commit-Queue: Nicolás Peña <npm@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

1 files changed, 17 insertions, 17 deletions

diff --git a/core/fpdfapi/parser/cpdf_syntax_parser_unittest.cpp b/core/fpdfapi/parser/cpdf_syntax_parser_unittest.cpp
index 249276f29a..ac7a875af6 100644
--- a/core/fpdfapi/parser/cpdf_syntax_parser_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_syntax_parser_unittest.cpp
@@ -21,7 +21,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 0, false), 0);
     EXPECT_EQ("", parser.ReadHexString());
-    EXPECT_EQ(0, parser.SavePos());
+    EXPECT_EQ(0, parser.GetPos());
   }
 
   {
@@ -30,7 +30,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 2, false), 0);
     EXPECT_EQ("", parser.ReadHexString());
-    EXPECT_EQ(2, parser.SavePos());
+    EXPECT_EQ(2, parser.GetPos());
   }
 
   {
@@ -39,7 +39,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 4, false), 0);
     EXPECT_EQ("\x12\xb0", parser.ReadHexString());
-    EXPECT_EQ(4, parser.SavePos());
+    EXPECT_EQ(4, parser.GetPos());
   }
 
   {
@@ -48,7 +48,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 10, false), 0);
     EXPECT_EQ("\x10", parser.ReadHexString());
-    EXPECT_EQ(10, parser.SavePos());
+    EXPECT_EQ(10, parser.GetPos());
   }
 
   {
@@ -57,7 +57,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 4, false), 0);
     EXPECT_EQ("\xab", parser.ReadHexString());
-    EXPECT_EQ(4, parser.SavePos());
+    EXPECT_EQ(4, parser.GetPos());
   }
 
   {
@@ -66,7 +66,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 4, false), 0);
     EXPECT_EQ("\xab", parser.ReadHexString());
-    EXPECT_EQ(4, parser.SavePos());
+    EXPECT_EQ(4, parser.GetPos());
   }
 
   {
@@ -75,7 +75,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 9, false), 0);
     EXPECT_EQ("\x1a\x2b", parser.ReadHexString());
-    EXPECT_EQ(5, parser.SavePos());
+    EXPECT_EQ(5, parser.GetPos());
   }
 
   {
@@ -83,20 +83,20 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     uint8_t data[] = "12ab>";
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 5, false), 0);
-    parser.RestorePos(5);
+    parser.SetPos(5);
     EXPECT_EQ("", parser.ReadHexString());
 
-    parser.RestorePos(6);
+    parser.SetPos(6);
     EXPECT_EQ("", parser.ReadHexString());
 
-    parser.RestorePos(-1);
+    parser.SetPos(-1);
     EXPECT_EQ("", parser.ReadHexString());
 
-    parser.RestorePos(std::numeric_limits<FX_FILESIZE>::max());
+    parser.SetPos(std::numeric_limits<FX_FILESIZE>::max());
     EXPECT_EQ("", parser.ReadHexString());
 
     // Check string still parses when set to 0.
-    parser.RestorePos(0);
+    parser.SetPos(0);
     EXPECT_EQ("\x12\xab", parser.ReadHexString());
   }
 
@@ -106,7 +106,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 4, false), 0);
     EXPECT_EQ("\x1a\x2b", parser.ReadHexString());
-    EXPECT_EQ(4, parser.SavePos());
+    EXPECT_EQ(4, parser.GetPos());
   }
 
   {
@@ -115,7 +115,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 5, false), 0);
     EXPECT_EQ("\x12\xab", parser.ReadHexString());
-    EXPECT_EQ(5, parser.SavePos());
+    EXPECT_EQ(5, parser.GetPos());
   }
 
   {
@@ -124,7 +124,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 8, false), 0);
     EXPECT_EQ("\x1a\x20", parser.ReadHexString());
-    EXPECT_EQ(4, parser.SavePos());
+    EXPECT_EQ(4, parser.GetPos());
   }
 
   {
@@ -133,7 +133,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 8, false), 0);
     EXPECT_EQ("\x1a\x2a\xdf", parser.ReadHexString());
-    EXPECT_EQ(8, parser.SavePos());
+    EXPECT_EQ(8, parser.GetPos());
   }
 
   {
@@ -142,7 +142,7 @@ TEST(cpdf_syntax_parser, ReadHexString) {
     CPDF_SyntaxParser parser;
     parser.InitParser(pdfium::MakeRetain<CFX_MemoryStream>(data, 1, false), 0);
     EXPECT_EQ("", parser.ReadHexString());
-    EXPECT_EQ(1, parser.SavePos());
+    EXPECT_EQ(1, parser.GetPos());
   }
 }