diff options
author | Tomaž Vajngerl <tomaz.vajngerl@collabora.co.uk> | 2021-03-02 18:57:46 +0900 |
---|---|---|
committer | Adolfo Jayme Barrientos <fitojb@ubuntu.com> | 2021-03-03 09:14:22 +0100 |
commit | ed7a3dabc8c35b8b33bad33fc26ebd8fb80b0cbd (patch) | |
tree | a55ef40cb7b548db0787a90c6dacc428e3cedaf0 | |
parent | 411c870ed16c6a27bbd9c762e187783b3b39849e (diff) |
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.
Change-Id: I61eb281e821ccd195ef006d778556e25d1c7f5e3
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111820
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
(cherry picked from commit 2c1ed5a5dad827cde032f27a4348e81be15889bc)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111857
Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>
-rw-r--r-- | vcl/inc/pdf/ExternalPDFStreams.hxx | 12 | ||||
-rw-r--r-- | vcl/source/filter/ipdf/pdfdocument.cxx | 12 | ||||
-rw-r--r-- | vcl/source/gdi/pdfwriter_impl.cxx | 12 |
3 files changed, 26 insertions, 10 deletions
diff --git a/vcl/inc/pdf/ExternalPDFStreams.hxx b/vcl/inc/pdf/ExternalPDFStreams.hxx index ab3d057bd83c..0a1997fe7dc7 100644 --- a/vcl/inc/pdf/ExternalPDFStreams.hxx +++ b/vcl/inc/pdf/ExternalPDFStreams.hxx @@ -33,21 +33,25 @@ 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_shared<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/source/filter/ipdf/pdfdocument.cxx b/vcl/source/filter/ipdf/pdfdocument.cxx index 41c44bd01b57..804713abaf10 100644 --- a/vcl/source/filter/ipdf/pdfdocument.cxx +++ b/vcl/source/filter/ipdf/pdfdocument.cxx @@ -1441,12 +1441,18 @@ 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 951cda0f29da..eeeb4305a181 100644 --- a/vcl/source/gdi/pdfwriter_impl.cxx +++ b/vcl/source/gdi/pdfwriter_impl.cxx @@ -8459,10 +8459,16 @@ 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"); |