Bug#342337: xpdf: Security hole CAN-2005-3193

[Jan Niehusmann]

On Thu, Dec 08, 2005 at 12:12:09AM +1100, Hamish Moffatt wrote:
> On Wed, Dec 07, 2005 at 02:00:55PM +0100, Jan Niehusmann wrote:
> > Ok, so you noticed that my analysis was not completely correct - while
> > the woody version indeed doesn't contain JPXStream.cc (and consequently,
> > the JPX stream reader bug doesn't exist in woody), the other security
> > holes (in Stream.cc) do exist in woody and need patching.
> 
> I'll work on that next, but it won't be for a day or two due to time
> constraints. It looks like a bit more work that woody. You are welcome
> to work on it if you like.

Well I don't have time to verify that all holes are actually closed, but
the attached patch applies cleanly, and the result does compile on sarge
(not tested on woody, as I don't have an installation available).

Jan


diff -ur xpdf-1.00-o/xpdf/Stream.cc xpdf-1.00/xpdf/Stream.cc
--- xpdf-1.00-o/xpdf/Stream.cc  2002-02-02 00:15:45.000000000 +0100
+++ xpdf-1.00/xpdf/Stream.cc    2005-12-07 15:34:21.000000000 +0100
@@ -400,18 +400,33 @@
 
 StreamPredictor::StreamPredictor(Stream *strA, int predictorA,
                                 int widthA, int nCompsA, int nBitsA) {
+  int totalBits;
+
   str = strA;
   predictor = predictorA;
   width = widthA;
   nComps = nCompsA;
   nBits = nBitsA;
+  predLine = NULL;
+  ok = gFalse;
 
   nVals = width * nComps;
+  totalBits = nVals * nBits;
+  if (totalBits == 0 ||
+      (totalBits / nBits) / nComps != width ||
+      totalBits + 7 < 0) {
+    return;
+  }
   pixBytes = (nComps * nBits + 7) >> 3;
-  rowBytes = ((nVals * nBits + 7) >> 3) + pixBytes;
+  rowBytes = ((totalBits + 7) >> 3) + pixBytes;
+  if (rowBytes < 0) {
+    return;
+  }
   predLine = (Guchar *)gmalloc(rowBytes);
   memset(predLine, 0, rowBytes);
   predIdx = rowBytes;
+
+  ok = gTrue;
 }
 
 StreamPredictor::~StreamPredictor() {
@@ -852,6 +867,10 @@
     FilterStream(strA) {
   if (predictor != 1) {
     pred = new StreamPredictor(this, predictor, columns, colors, bits);
+    if (!pred->isOk()) {
+      delete pred;
+      pred = NULL;
+    }
   } else {
     pred = NULL;
   }
@@ -2535,6 +2554,14 @@
   height = read16();
   width = read16();
   numComps = str->getChar();
+  if (numComps <= 0 || numComps > 4) {
+    error(getPos(), "Bad number of components in DCT stream", prec);
+    return gFalse;
+  }
+  if (numComps <= 0 || numComps > 4) {
+    error(getPos(), "Bad number of components in DCT stream", prec);
+    return gFalse;
+  }
   length -= 6;
   if (prec != 8) {
     error(getPos(), "Bad DCT precision %d", prec);
@@ -2815,6 +2842,10 @@
     FilterStream(strA) {
   if (predictor != 1) {
     pred = new StreamPredictor(this, predictor, columns, colors, bits);
+    if (!pred->isOk()) {
+      delete pred;
+      pred = NULL;
+    }
   } else {
     pred = NULL;
   }
diff -ur xpdf-1.00-o/xpdf/Stream.h xpdf-1.00/xpdf/Stream.h
--- xpdf-1.00-o/xpdf/Stream.h   2002-02-02 00:15:45.000000000 +0100
+++ xpdf-1.00/xpdf/Stream.h     2005-12-07 15:34:21.000000000 +0100
@@ -214,6 +214,8 @@
 
   ~StreamPredictor();
 
+  GBool isOk() { return ok; }
+
   int lookChar();
   int getChar();
 
@@ -231,6 +233,7 @@
   int rowBytes;                        // bytes per line
   Guchar *predLine;            // line buffer
   int predIdx;                 // current index in predLine
+  GBool ok;
 };
 
 //------------------------------------------------------------------------