Commit ac385ca6 authored by Thomas Finch's avatar Thomas Finch Committed by Don Hinton
Browse files

Fix null dereference in yaml::Document::skip 

Summary: The attached test case replicates a null dereference crash in
`yaml::Document::skip()`. This was fixed by adding a check and early
return in the method.

Reviewers: Bigcheese, hintonda, beanz

Reviewed By: hintonda

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69974
parent 6ebec32b

llvm/lib/Support/YAMLParser.cpp

+2 −2
Original line number Diff line number Diff line
@@ -2288,8 +2288,8 @@ Document::Document(Stream &S) : stream(S), Root(nullptr) { 
bool Document::skip()  {

  if (stream.scanner->failed())

    return false;

  if (!Root)

    getRoot();

  if (!Root && !getRoot())

    return false;

  Root->skip();

  Token &T = peekNext();

  if (T.Kind == Token::TK_StreamEnd)

llvm/unittests/Support/YAMLParserTest.cpp

+11 −0
Original line number Diff line number Diff line
@@ -331,4 +331,15 @@ TEST(YAMLParser, DifferentNodesIteratorOperatorEquals) { 
  EXPECT_TRUE(End == AnotherEnd);

}



TEST(YAMLParser, FlowSequenceTokensOutsideFlowSequence) {

  auto FlowSequenceStrs = {",", "]", "}"};

  SourceMgr SM;



  for (auto &Str : FlowSequenceStrs) {

    yaml::Stream Stream(Str, SM);

    yaml::Document &Doc = *Stream.begin();

    EXPECT_FALSE(Doc.skip());

  }

}



} // end namespace llvm