From d3ab0f383f6736657480a8bb418c5e715a1aed3b Mon Sep 17 00:00:00 2001 From: Wei Li Date: Mon, 11 Jan 2016 14:05:41 -0800 Subject: Fix an infinite loop parsing in CPDF_SyntaxParser::GetObject() CPDF_SyntaxParser::GetObject() may enter into an infinite loop when a signature dictionary doesn't have 'Contents' field. Add a check to avoid that. BUG=pdfium:344 R=thestig@chromium.org Review URL: https://codereview.chromium.org/1575833004 . --- core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp | 7 ++++--- fpdfsdk/src/fpdfview_embeddertest.cpp | 6 ++++++ testing/resources/bug_344.pdf | 9 +++++++++ 3 files changed, 19 insertions(+), 3 deletions(-) create mode 100644 testing/resources/bug_344.pdf diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp index 3ab4423172..49d6760c65 100644 --- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp +++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp @@ -2163,12 +2163,13 @@ CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjects* pObjList, pDict->SetAt(keyNoSlash, pObj); } - if (IsSignatureDict(pDict.get())) { - FX_FILESIZE dwSavePos = m_Pos; + // Only when this is a signature dictionary and has contents, we reset the + // contents to the un-decrypted form. + if (IsSignatureDict(pDict.get()) && dwSignValuePos) { + CFX_AutoRestorer save_pos(&m_Pos); m_Pos = dwSignValuePos; CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, nullptr, FALSE); pDict->SetAt("Contents", pObj); - m_Pos = dwSavePos; } if (pContext) { pContext->m_DictEnd = m_Pos; diff --git a/fpdfsdk/src/fpdfview_embeddertest.cpp b/fpdfsdk/src/fpdfview_embeddertest.cpp index 6a6d076983..3147c01660 100644 --- a/fpdfsdk/src/fpdfview_embeddertest.cpp +++ b/fpdfsdk/src/fpdfview_embeddertest.cpp @@ -221,4 +221,10 @@ TEST_F(FPDFViewEmbeddertest, CrossRefV4Loop) { // cause infinite loop. TEST_F(FPDFViewEmbeddertest, Hang_343) { EXPECT_FALSE(OpenDocument("bug_343.pdf")); +} + +// The test should pass when the absence of 'Contents' field in a signature +// dictionary will not cause an infinite loop in CPDF_SyntaxParser::GetObject(). +TEST_F(FPDFViewEmbeddertest, Hang_344) { + EXPECT_FALSE(OpenDocument("bug_344.pdf")); } \ No newline at end of file diff --git a/testing/resources/bug_344.pdf b/testing/resources/bug_344.pdf new file mode 100644 index 0000000000..c015c66791 --- /dev/null +++ b/testing/resources/bug_344.pdf @@ -0,0 +1,9 @@ +'%PDF-1.6 +%âãÏÓ +<<0 0 objParams%PDF-2.4 +trailer% +<>ta>>%%sPsP \ No newline at end of file -- cgit v1.2.3