Add Inflator::BadDistanceErr exception (Issue 414)

The improved validation and excpetion clears the Address Sanitizer and Undefined Behavior Sanitizer findings

1 files changed, 7 insertions, 1 deletions

diff --git a/zinflate.cpp b/zinflate.cpp
index 62431771..ee15c945 100644
--- a/zinflate.cpp
+++ b/zinflate.cpp
@@ -552,12 +552,18 @@ bool Inflator::DecodeBody()
 		case DISTANCE_BITS:

 					// TODO: this surfaced during fuzzing. What do we do???

 					CRYPTOPP_ASSERT(m_distance < COUNTOF(distanceExtraBits));

-					bits = (m_distance >= COUNTOF(distanceExtraBits)) ? distanceExtraBits[29] : distanceExtraBits[m_distance];

+					if (m_distance >= COUNTOF(distanceExtraBits))

+						throw BadDistanceErr();

+					bits = distanceExtraBits[m_distance];

 					if (!m_reader.FillBuffer(bits))

 					{

 						m_nextDecode = DISTANCE_BITS;

 						break;

 					}

+					// TODO: this surfaced during fuzzing. What do we do???

+					CRYPTOPP_ASSERT(m_distance < COUNTOF(distanceStarts));

+					if (m_distance >= COUNTOF(distanceStarts))

+						throw BadDistanceErr();

 					m_distance = m_reader.GetBits(bits) + distanceStarts[m_distance];

 					OutputPast(m_literal, m_distance);

 				}