[fix](inverted index) special characters cause buffer overflow in Uni…

…code tokenization. (#211)
apache · May 1, 2024 · f10bc3f · f10bc3f
1 parent 847f460
commit f10bc3f
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Showing 6 changed files with 39 additions and 61 deletions.
diff --git a/src/core/CLucene/analysis/AnalysisHeader.h b/src/core/CLucene/analysis/AnalysisHeader.h
@@ -11,6 +11,8 @@
 #include "CLucene/util/VoidList.h"
 #include "CLucene/LuceneThreads.h"
 
+#include <unordered_set>
+
 CL_CLASS_DEF(util,Reader)
 CL_CLASS_DEF(util,IReader)
 
@@ -297,6 +299,11 @@ class CLUCENE_EXPORT Analyzer{
     virtual void set_lowercase(bool lowercase) {
         _lowercase = lowercase;
     }
+
+    virtual void set_stopwords(std::unordered_set<std::string_view>* stopwords) {
+        _stopwords = stopwords;
+    }
+
 private:
 
     DEFINE_MUTEX(THIS_LOCK)
@@ -313,7 +320,9 @@ class CLUCENE_EXPORT Analyzer{
 	*  to save a TokenStream for later re-use by the same
 	*  thread. */
     virtual void setPreviousTokenStream(TokenStream* obj);
+
     bool _lowercase = false;
+    std::unordered_set<std::string_view>* _stopwords = nullptr;
 
 public:
     /**
@@ -350,6 +359,7 @@ class CLUCENE_EXPORT Tokenizer:public TokenStream {
     /** The text source for this Tokenizer. */
     CL_NS(util)::Reader* input;
     bool lowercase = false;
+    std::unordered_set<std::string_view>* stopwords = nullptr;
 
 public:
     /** Construct a tokenizer with null input. */

diff --git a/src/core/CLucene/analysis/standard95/StandardAnalyzer.h b/src/core/CLucene/analysis/standard95/StandardAnalyzer.h
@@ -6,18 +6,22 @@ namespace lucene::analysis::standard95 {
 
 class StandardAnalyzer : public Analyzer {
  public:
-     StandardAnalyzer() : Analyzer() { _lowercase = true; }
+  StandardAnalyzer() : Analyzer() { 
+    _lowercase = true;
+    _stopwords = nullptr;
+  }
+
   bool isSDocOpt() override { return true; }
 
   TokenStream* tokenStream(const TCHAR* fieldName,
                            lucene::util::Reader* reader) override {
-    return _CLNEW StandardTokenizer(reader, useStopWords_, _lowercase);
+    return _CLNEW StandardTokenizer(reader, _lowercase, _stopwords);
   }
 
   TokenStream* reusableTokenStream(const TCHAR* fieldName,
                                    lucene::util::Reader* reader) override {
     if (tokenizer_ == nullptr) {
-      tokenizer_ = new StandardTokenizer(reader, useStopWords_, _lowercase);
+      tokenizer_ = new StandardTokenizer(reader, _lowercase, _stopwords);
     } else {
       tokenizer_->reset(reader);
     }
@@ -31,13 +35,7 @@ class StandardAnalyzer : public Analyzer {
     }
   }
 
-  void useStopWords(bool useStopWords) {
-    useStopWords_ = useStopWords;
-  }
-
  private:
-  bool useStopWords_ = true;
-
   StandardTokenizer* tokenizer_ = nullptr;
 };
 

diff --git a/src/core/CLucene/analysis/standard95/StandardTokenizer.h b/src/core/CLucene/analysis/standard95/StandardTokenizer.h
@@ -19,15 +19,17 @@ static std::unordered_set<std::string_view> stop_words = {
 
 class StandardTokenizer : public Tokenizer {
  public:
-  StandardTokenizer(lucene::util::Reader* in, bool useStopWords)
-      : Tokenizer(in), useStopWords_(useStopWords) {
+  StandardTokenizer(lucene::util::Reader* in)
+      : Tokenizer(in) {
     scanner_ = std::make_unique<StandardTokenizerImpl>(in);
     Tokenizer::lowercase = true;
+    Tokenizer::stopwords = nullptr;
   }
-  StandardTokenizer(lucene::util::Reader* in, bool useStopWords, bool lowercase)
-          : Tokenizer(in), useStopWords_(useStopWords) {
+  StandardTokenizer(lucene::util::Reader* in, bool lowercase, std::unordered_set<std::string_view>* stopwords)
+          : Tokenizer(in) {
       scanner_ = std::make_unique<StandardTokenizerImpl>(in);
       Tokenizer::lowercase = lowercase;
+      Tokenizer::stopwords = stopwords;
   }
 
   Token* next(Token* token) override {
@@ -47,7 +49,7 @@ class StandardTokenizer : public Tokenizer {
             std::transform(term.begin(), term.end(), const_cast<char*>(term.data()),
                            [](char c) { return to_lower(c); });
           }
-          if (useStopWords_ && stop_words.count(term)) {
+          if (stopwords && stopwords->count(term)) {
             skippedPositions++;
             continue;
           }
@@ -70,8 +72,6 @@ class StandardTokenizer : public Tokenizer {
   };
 
  private:
-  bool useStopWords_ = true;
-
   std::unique_ptr<StandardTokenizerImpl> scanner_;
 
   int32_t skippedPositions = 0;

diff --git a/src/core/CLucene/analysis/standard95/StandardTokenizerImpl.cpp b/src/core/CLucene/analysis/standard95/StandardTokenizerImpl.cpp
@@ -58,7 +58,7 @@ const std::vector<std::string> StandardTokenizerImpl::ZZ_ERROR_MSG = {
     "Error: pushback value was too large"};
 
 StandardTokenizerImpl::StandardTokenizerImpl(lucene::util::Reader* reader)
-    : zzBuffer(ZZ_BUFFERSIZE), zzReader(reader) {}
+    : zzReader(reader), zzBuffer((reader == nullptr) ? 0 : reader->size()) {}
 
 std::string_view StandardTokenizerImpl::getText() {
   return std::string_view(zzBuffer.data() + zzStartRead,
@@ -67,53 +67,20 @@ std::string_view StandardTokenizerImpl::getText() {
 
 bool StandardTokenizerImpl::zzRefill() {
   if (zzStartRead > 0) {
-    zzEndRead += zzFinalHighSurrogate;
-    zzFinalHighSurrogate = 0;
-    std::copy_n(zzBuffer.begin() + zzStartRead, zzEndRead - zzStartRead,
-                zzBuffer.begin());
-
-    zzEndRead -= zzStartRead;
-    zzCurrentPos -= zzStartRead;
-    zzMarkedPos -= zzStartRead;
-    zzStartRead = 0;
-  }
-
-  int32_t requested = zzBuffer.size() - zzEndRead - zzFinalHighSurrogate;
-  if (requested == 0) {
-    return true;
+      return true;
   }
 
-  int32_t numRead = zzReader->readCopy(zzBuffer.data(), zzEndRead, requested);
-  if (numRead == 0) {
-    _CLTHROWA(CL_ERR_Runtime,
-              "Reader returned 0 characters. See JFlex examples/zero-reader "
-              "for a workaround.");
-  }
+  int32_t numRead = zzReader->readCopy(zzBuffer.data(), 0, zzBuffer.size());
   if (numRead > 0) {
-    zzEndRead += numRead;
-
-    int32_t n =
-        StringUtil::validate_utf8(std::string_view(zzBuffer.data(), zzEndRead));
-    if (n == -1) {
-      yyResetPosition();
-      return true;
-    }
+      assert(zzBuffer.size() == numRead);
+      zzEndRead += numRead;
 
-    if (n != 0) {
-      if (numRead == requested) {
-        zzEndRead -= n;
-        zzFinalHighSurrogate = n;
-      } else {
-        int32_t c = zzReader->read();
-        if (c == -1) {
+      int32_t n = StringUtil::validate_utf8(std::string_view(zzBuffer.data(), zzBuffer.size()));
+      if (n != 0) {
           return true;
-        } else {
-          _CLTHROWA(CL_ERR_Runtime, "Why did you come here");
-        }
       }
-    }
 
-    return false;
+      return false;
   }
 
   return true;
@@ -126,6 +93,7 @@ void StandardTokenizerImpl::yyclose() {
 
 void StandardTokenizerImpl::yyreset(lucene::util::Reader* reader) {
   zzReader = reader;
+  zzBuffer.resize(reader->size());
   yyResetPosition();
   zzLexicalState = YYINITIAL;
 }
@@ -181,7 +149,7 @@ int32_t StandardTokenizerImpl::getNextToken() {
 
     {
       while (true) {
-        if (zzCurrentPosL < zzEndReadL) {
+        if (zzCurrentPosL < zzEndReadL && (zzCurrentPosL - zzStartRead) < ZZ_BUFFERSIZE) {
           size_t len = 0;
           zzInput = decodeUtf8ToCodepoint(
               std::string_view(zzBufferL.data() + zzCurrentPosL, zzEndReadL),

diff --git a/src/core/CLucene/util/stringUtil.h b/src/core/CLucene/util/stringUtil.h
@@ -296,10 +296,10 @@ class StringUtil {
             } else {
                 if ((c & 0xC0) != 0x80) return -1;
                 codepoint = (codepoint << 6) | (c & 0x3F);
-                if (!is_valid_codepoint(codepoint)) {
+                bytes_in_char--;
+                if (bytes_in_char == 0 && !is_valid_codepoint(codepoint)) {
                     return -1;
                 }
-                bytes_in_char--;
                 surplus_bytes++;
             }
         }

diff --git a/src/test/analysis/TestStandard95.cpp b/src/test/analysis/TestStandard95.cpp
@@ -3,11 +3,13 @@
 
 #include "CLucene/_ApiHeader.h"
 #include "CLucene/analysis/standard95/StandardAnalyzer.h"
+#include "CLucene/analysis/standard95/StandardTokenizer.h"
 #include "test.h"
 
 void testCut(const std::string &str, std::vector<std::string> &tokens) {
   auto standard =
       std::make_unique<lucene::analysis::standard95::StandardAnalyzer>();
+  standard->set_stopwords(&lucene::analysis::standard95::stop_words);
   auto tokenizer =
       static_cast<lucene::analysis::standard95::StandardTokenizer *>(
           standard->tokenStream(L"name", nullptr));
@@ -28,7 +30,7 @@ void testCut(const std::string &str, std::vector<std::string> &tokens) {
 void testCutLines(std::vector<std::string>& datas, std::vector<std::string> &tokens) {
   auto standard =
       std::make_unique<lucene::analysis::standard95::StandardAnalyzer>();
-  standard->useStopWords(false);
+  standard->set_stopwords(nullptr);
   auto tokenizer =
       static_cast<lucene::analysis::standard95::StandardTokenizer *>(
           standard->tokenStream(L"name", nullptr));