vcl/inc/pdf/ExternalPDFStreams.hxx | 12 ++++++++---- vcl/qa/cppunit/PDFDocumentTest.cxx | 12 ++++++++++++ vcl/qa/cppunit/data/DocumentWithNull.pdf |binary vcl/source/filter/ipdf/pdfdocument.cxx | 12 +++++++++--- vcl/source/gdi/pdfwriter_impl.cxx | 12 +++++++++--- 5 files changed, 38 insertions(+), 10 deletions(-)
New commits: commit 90267d3dee8c0afe937c9aecb8561f6f158977f9 Author: Tomaž Vajngerl <tomaz.vajng...@collabora.co.uk> AuthorDate: Tue Mar 2 18:57:46 2021 +0900 Commit: Tomaž Vajngerl <qui...@gmail.com> CommitDate: Sat Mar 13 03:49:41 2021 +0100 tdf#140606 make PDF parsing more lenient and prevent a crash If the external document can't be opened, it tried to continue with the export anyway, which eventually lead to a crash. This is fixed by handling this situation and prevent a crash, however the part of the document in this case isn't exported. The document couldn't be opened because of a parsing error - there was a unexpected null character instead of a whitespace, which made the parser panic. Fix this by making the parser more lenient in such a situation when there is an unexpected null and try to continue parsing. Bug document seems to be created with a buggy PDF writer, but other PDF readers don't complain when parsing the document so it looks to be a valid. qpdf --check doesn't complain either. Added a test that checks a document with a null parses. Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111820 Tested-by: Jenkins Reviewed-by: Tomaž Vajngerl <qui...@gmail.com> (cherry picked from commit 2c1ed5a5dad827cde032f27a4348e81be15889bc) Change-Id: I61eb281e821ccd195ef006d778556e25d1c7f5e3 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112418 Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoff...@gmail.com> Reviewed-by: Tomaž Vajngerl <qui...@gmail.com> diff --git a/vcl/inc/pdf/ExternalPDFStreams.hxx b/vcl/inc/pdf/ExternalPDFStreams.hxx index 3bd59478c212..de0819539e76 100644 --- a/vcl/inc/pdf/ExternalPDFStreams.hxx +++ b/vcl/inc/pdf/ExternalPDFStreams.hxx @@ -29,21 +29,25 @@ struct VCL_DLLPUBLIC ExternalPDFStream std::map<sal_Int32, sal_Int32>& getCopiedResources() { return maCopiedResources; } - filter::PDFDocument& getPDFDocument() + std::shared_ptr<filter::PDFDocument>& getPDFDocument() { if (!mpPDFDocument) { SvMemoryStream aPDFStream; aPDFStream.WriteBytes(maData.data(), maData.size()); aPDFStream.Seek(0); - mpPDFDocument = std::make_unique<filter::PDFDocument>(); - if (!mpPDFDocument->Read(aPDFStream)) + auto pPDFDocument = std::make_shared<filter::PDFDocument>(); + if (!pPDFDocument->Read(aPDFStream)) { SAL_WARN("vcl.pdfwriter", "PDFWriterImpl::writeReferenceXObject: reading the PDF document failed"); } + else + { + mpPDFDocument = pPDFDocument; + } } - return *mpPDFDocument; + return mpPDFDocument; } }; diff --git a/vcl/qa/cppunit/PDFDocumentTest.cxx b/vcl/qa/cppunit/PDFDocumentTest.cxx index 66de7dfc77d4..9b0374f00341 100644 --- a/vcl/qa/cppunit/PDFDocumentTest.cxx +++ b/vcl/qa/cppunit/PDFDocumentTest.cxx @@ -156,6 +156,18 @@ CPPUNIT_TEST_FIXTURE(PDFDocumentTest, testParseBasicPDF) } } +CPPUNIT_TEST_FIXTURE(PDFDocumentTest, testParseDocumentWithNullAsWhitespace) +{ + // tdf#140606 + // Bug document contained a null, which cause the parser to panic, + // but other PDF readers can handle the file well. + + OUString aURL = m_directories.getURLFromSrc(DATA_DIRECTORY) + "DocumentWithNull.pdf"; + vcl::filter::PDFDocument aDocument; + SvFileStream aStream(aURL, StreamMode::READ); + CPPUNIT_ASSERT(aDocument.Read(aStream)); +} + namespace { vcl::filter::PDFObjectElement* diff --git a/vcl/qa/cppunit/data/DocumentWithNull.pdf b/vcl/qa/cppunit/data/DocumentWithNull.pdf new file mode 100644 index 000000000000..f6d926957366 Binary files /dev/null and b/vcl/qa/cppunit/data/DocumentWithNull.pdf differ diff --git a/vcl/source/filter/ipdf/pdfdocument.cxx b/vcl/source/filter/ipdf/pdfdocument.cxx index dd1355d924a8..64cf9dc4ef90 100644 --- a/vcl/source/filter/ipdf/pdfdocument.cxx +++ b/vcl/source/filter/ipdf/pdfdocument.cxx @@ -1327,12 +1327,18 @@ bool PDFDocument::Tokenize(SvStream& rStream, TokenizeMode eMode, } else { - if (!rtl::isAsciiWhiteSpace(static_cast<unsigned char>(ch))) + auto uChar = static_cast<unsigned char>(ch); + // Be more lenient and allow unexpected null char + if (!rtl::isAsciiWhiteSpace(uChar) && uChar != 0) { - SAL_WARN("vcl.filter", "PDFDocument::Tokenize: unexpected character: " - << ch << " at byte position " << rStream.Tell()); + SAL_WARN("vcl.filter", + "PDFDocument::Tokenize: unexpected character with code " + << sal_Int32(ch) << " at byte position " << rStream.Tell()); return false; } + SAL_WARN_IF(uChar == 0, "vcl.filter", + "PDFDocument::Tokenize: unexpected null character at " + << rStream.Tell() << " - ignoring"); } break; } diff --git a/vcl/source/gdi/pdfwriter_impl.cxx b/vcl/source/gdi/pdfwriter_impl.cxx index 2aa973e567c5..cfc8ffeffedc 100644 --- a/vcl/source/gdi/pdfwriter_impl.cxx +++ b/vcl/source/gdi/pdfwriter_impl.cxx @@ -8686,10 +8686,16 @@ void PDFWriterImpl::writeReferenceXObject(ReferenceXObjectEmit& rEmit) // object. if (rEmit.m_nExternalPDFDataIndex < 0) return; - auto & rExternalPDFStream = m_aExternalPDFStreams.get(rEmit.m_nExternalPDFDataIndex); - auto & rPDFDocument = rExternalPDFStream.getPDFDocument(); + auto& rExternalPDFStream = m_aExternalPDFStreams.get(rEmit.m_nExternalPDFDataIndex); + auto& pPDFDocument = rExternalPDFStream.getPDFDocument(); + if (!pPDFDocument) + { + // Couldn't parse the document and can't continue + SAL_WARN("vcl.pdfwriter", "PDFWriterImpl::writeReferenceXObject: failed to parse the document"); + return; + } - std::vector<filter::PDFObjectElement*> aPages = rPDFDocument.GetPages(); + std::vector<filter::PDFObjectElement*> aPages = pPDFDocument->GetPages(); if (aPages.empty()) { SAL_WARN("vcl.pdfwriter", "PDFWriterImpl::writeReferenceXObject: no pages"); _______________________________________________ Libreoffice-commits mailing list libreoffice-comm...@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/libreoffice-commits