Added more checks to readVarint

src/util.h

@@ -186,6 +186,11 @@ const uint8_t* readVarint(const uint8_t* data, const uint8_t* data_end, T& b)
 		}
 
 		const uint64_t cur_byte = *(data++);
+
+		if (k && (cur_byte == 0)) {
+			return nullptr;
+		}
+
 		result |= (cur_byte & 0x7F) << k;
 
 		if ((k > 0) && (shiftleft128(cur_byte & 0x7F, 0, k) != 0)) {

tests/src/util_tests.cpp

@@ -90,6 +90,14 @@ TEST(util, varint)
 	uint32_t check2;
 	uint8_t buf4[] = {255, 255, 255, 255, 127};
 	ASSERT_EQ(readVarint(buf4, buf4 + sizeof(buf4), check2), nullptr);
+
+	// Invalid value 5
+	uint8_t buf5[] = {128, 0};
+	ASSERT_EQ(readVarint(buf5, buf5 + sizeof(buf5), check), nullptr);
+
+	// Invalid value 6 (2^64)
+	uint8_t buf6[] = {128, 128, 128, 128, 128, 128, 128, 128, 128, 2};
+	ASSERT_EQ(readVarint(buf6, buf6 + sizeof(buf6), check), nullptr);
 }
 
 TEST(util, bsr)