commit c3577325de5b9d59539c2413dcc66283df062ffa
author LE GARREC Vincent <gitlab-freedesktop@le-garrec.fr> Sun Jan 27 10:19:10 2019 +0000
committer Albert Astals Cid <tsdgeos@yahoo.es> Sun Jan 27 10:19:10 2019 +0000
tree aff30816e1b813c13f3d35c1c606227135abd4f9
parent a73c80e024e8b2a9613926793165da07017dfbb2

ofz-8725: Undefined-shift in JBIG2HuffmanDecoder::buildTable

poppler/JBIG2Stream.cc

diff --git a/poppler/JBIG2Stream.cc b/poppler/JBIG2Stream.cc
index a5329ae..9670e89 100644
--- a/poppler/JBIG2Stream.cc
+++ b/poppler/JBIG2Stream.cc
@@ -327,7 +327,7 @@
   unsigned int readBit();
 
   // Sort the table by prefix length and assign prefix values.
-  void buildTable(JBIG2HuffmanTable *table, unsigned int len);
+  static bool buildTable(JBIG2HuffmanTable *table, unsigned int len);
 
 private:
 
@@ -412,7 +412,7 @@
   return (buf >> bufLen) & 1;
 }
 
-void JBIG2HuffmanDecoder::buildTable(JBIG2HuffmanTable *table, unsigned int len) {
+bool JBIG2HuffmanDecoder::buildTable(JBIG2HuffmanTable *table, unsigned int len) {
   unsigned int i, j, k, prefix;
   JBIG2HuffmanTable tab;
 
@@ -448,10 +448,17 @@
     prefix = 0;
     table[i++].prefix = prefix++;
     for (; table[i].rangeLen != jbig2HuffmanEOT; ++i) {
-      prefix <<= table[i].prefixLen - table[i-1].prefixLen;
+      if (table[i].prefixLen - table[i-1].prefixLen > 32) {
+	error(errSyntaxError, -1, "Failed to build table for JBIG2 stream");
+	return false;
+      } else {
+	prefix <<= table[i].prefixLen - table[i-1].prefixLen;
+      }
       table[i].prefix = prefix++;
     }
   }
+
+  return true;
 }
 
 //------------------------------------------------------------------------
@@ -2007,7 +2014,7 @@
 				    unsigned int *refSegs, unsigned int nRefSegs) {
   JBIG2Bitmap *bitmap;
   JBIG2HuffmanTable runLengthTab[36];
-  JBIG2HuffmanTable *symCodeTab;
+  JBIG2HuffmanTable *symCodeTab = nullptr;
   JBIG2HuffmanTable *huffFSTable, *huffDSTable, *huffDTTable;
   JBIG2HuffmanTable *huffRDWTable, *huffRDHTable;
   JBIG2HuffmanTable *huffRDXTable, *huffRDYTable, *huffRSizeTable;
@@ -2229,7 +2236,12 @@
     runLengthTab[34].rangeLen = 7;
     runLengthTab[35].prefixLen = 0;
     runLengthTab[35].rangeLen = jbig2HuffmanEOT;
-    huffDecoder->buildTable(runLengthTab, 35);
+    if (!JBIG2HuffmanDecoder::buildTable(runLengthTab, 35)) {
+      huff = false;
+    }
+  }
+
+  if (huff) {
     symCodeTab = (JBIG2HuffmanTable *)gmallocn(numSyms + 1,
 					       sizeof(JBIG2HuffmanTable));
     for (i = 0; i < numSyms; ++i) {
@@ -2255,12 +2267,17 @@
     }
     symCodeTab[numSyms].prefixLen = 0;
     symCodeTab[numSyms].rangeLen = jbig2HuffmanEOT;
-    huffDecoder->buildTable(symCodeTab, numSyms);
+    if (!JBIG2HuffmanDecoder::buildTable(symCodeTab, numSyms)) {
+      huff = false;
+      gfree(symCodeTab);
+      symCodeTab = nullptr;
+    }
     huffDecoder->reset();
 
   // set up the arithmetic decoder
-  } else {
-    symCodeTab = nullptr;
+  }
+
+  if (!huff) {
     resetIntStats(symCodeLen);
     arithDecoder->start();
   }
@@ -4130,10 +4147,10 @@
   huffTab[i].val = 0;
   huffTab[i].prefixLen = 0;
   huffTab[i].rangeLen = jbig2HuffmanEOT;
-  huffDecoder->buildTable(huffTab, i);
-
-  // create and store the new table segment
-  segments->push_back(new JBIG2CodeTable(segNum, huffTab));
+  if (JBIG2HuffmanDecoder::buildTable(huffTab, i)) {
+    // create and store the new table segment
+    segments->push_back(new JBIG2CodeTable(segNum, huffTab));
+  }
 
   return;