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[Bitcode] Diagnose errors instead of asserting from bad input 

Eventually we can make some of these pass the error along to the caller.

Reports a fatal error if:
We find an invalid abbrev record
We try to get an invalid abbrev number
We can't fill the current word due to an EOF

Fixed an invalid bitcode test to check for output with FileCheck

Bugs found with afl-fuzz

llvm-svn: 226986
This commit is contained in:
Filipe Cabecinhas 2015-01-24 04:15:05 +00:00
parent d1787adcec
commit de968ecb05
6 changed files with 25 additions and 6 deletions
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9
llvm/include/llvm/Bitcode/BitstreamReader.h
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@ -315,7 +315,8 @@ public:
}
void fillCurWord() {
assert(Size == 0 || NextChar < (unsigned)Size);
if (Size != 0 && NextChar >= (unsigned)Size)
report_fatal_error("Unexpected end of file");
// Read the next word from the stream.
uint8_t Array[sizeof(word_t)] = {0};
@ -490,11 +491,11 @@ private:
//===--------------------------------------------------------------------===//
public:
/// Return the abbreviation for the specified AbbrevId.
const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
unsigned AbbrevNo = AbbrevID-bitc::FIRST_APPLICATION_ABBREV;
assert(AbbrevNo < CurAbbrevs.size() && "Invalid abbrev #!");
unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
if (AbbrevNo >= CurAbbrevs.size())
report_fatal_error("Invalid abbrev number");
return CurAbbrevs[AbbrevNo].get();
}

6
llvm/lib/Bitcode/Reader/BitstreamReader.cpp
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@ -170,8 +170,12 @@ unsigned BitstreamCursor::readRecord(unsigned AbbrevID,
unsigned Code;
if (CodeOp.isLiteral())
Code = CodeOp.getLiteralValue();
else
else {
if (CodeOp.getEncoding() == BitCodeAbbrevOp::Array ||
CodeOp.getEncoding() == BitCodeAbbrevOp::Blob)
report_fatal_error("Abbreviation starts with an Array or a Blob");
Code = readAbbreviatedField(*this, CodeOp);
}
for (unsigned i = 1, e = Abbv->getNumOperandInfos(); i != e; ++i) {
const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);

BIN
llvm/test/Bitcode/Inputs/invalid-abbrev.bc Normal file
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Binary file not shown.

1
llvm/test/Bitcode/Inputs/invalid-bad-abbrev-number.bc Normal file
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@ -0,0 +1 @@
BCﾀﾞ!0000000000

1
llvm/test/Bitcode/Inputs/invalid-unexpected-eof.bc Normal file
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@ -0,0 +1 @@
BCﾀﾞ! 000000 00000000000000

14
llvm/test/Bitcode/invalid.test
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@ -1 +1,13 @@
RUN: not llvm-dis -disable-output %p/Inputs/invalid-pr20485.bc
RUN: not llvm-dis -disable-output %p/Inputs/invalid-pr20485.bc 2>&1 | \
RUN: FileCheck --check-prefix=INVALID-ENCODING %s
RUN: not llvm-dis -disable-output %p/Inputs/invalid-abbrev.bc 2>&1 | \
RUN: FileCheck --check-prefix=BAD-ABBREV %s
RUN: not llvm-dis -disable-output %p/Inputs/invalid-unexpected-eof.bc 2>&1 | \
RUN: FileCheck --check-prefix=UNEXPECTED-EOF %s
RUN: not llvm-dis -disable-output %p/Inputs/invalid-bad-abbrev-number.bc 2>&1 | \
RUN: FileCheck --check-prefix=BAD-ABBREV-NUMBER %s
INVALID-ENCODING: Invalid encoding
BAD-ABBREV: Abbreviation starts with an Array or a Blob
UNEXPECTED-EOF: Unexpected end of file
BAD-ABBREV-NUMBER: Invalid abbrev number