* libtiff/tif_predict.h, libtiff/tif_predict.c:

Replace assertions by runtime checks to avoid assertions in debug mode,
or buffer overflows in release mode. Can happen when dealing with
unusual tile size like YCbCr with subsampling. Reported as MSVR 35105
by Axel Souchet	& Vishal Chauhan from the MSRC Vulnerabilities & Mitigations
team.

3 files changed, 123 insertions, 49 deletions

diff --git a/ChangeLog b/ChangeLog
index d33b4728..0379c3b7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2016-10-31 Even Rouault <even.rouault at spatialys.com>
+
+	* libtiff/tif_predict.h, libtiff/tif_predict.c:
+	Replace assertions by runtime checks to avoid assertions in debug mode,
+	or buffer overflows in release mode. Can happen when dealing with
+	unusual tile size like YCbCr with subsampling. Reported as MSVR 35105
+	by Axel Souchet	& Vishal Chauhan from the MSRC Vulnerabilities & Mitigations
+	team.
+
 2016-10-26 Even Rouault <even.rouault at spatialys.com>
 
 	* tools/fax2tiff.c: fix segfault when specifying -r without
diff --git a/libtiff/tif_predict.c b/libtiff/tif_predict.c
index 72571f42..1e16854d 100644
--- a/libtiff/tif_predict.c
+++ b/libtiff/tif_predict.c
@@ -1,4 +1,4 @@
-/* $Id: tif_predict.c,v 1.38 2016-09-24 23:11:55 bfriesen Exp $ */
+/* $Id: tif_predict.c,v 1.39 2016-10-31 17:24:26 erouault Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -34,18 +34,18 @@
 
 #define	PredictorState(tif)	((TIFFPredictorState*) (tif)->tif_data)
 
-static void horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void swabHorDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void swabHorDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc);
-static void fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int swabHorDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int swabHorDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc);
+static int fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc);
 static int PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);
 static int PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);
 static int PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s);
@@ -273,13 +273,19 @@ PredictorSetupEncode(TIFF* tif)
 /* - when storing into the byte stream, we explicitly mask with 0xff so */
 /*   as to make icc -check=conversions happy (not necessary by the standard) */
 
-static void
+static int
 horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	tmsize_t stride = PredictorState(tif)->stride;
 
 	unsigned char* cp = (unsigned char*) cp0;
-	assert((cc%stride)==0);
+    if((cc%stride)!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "horAcc8",
+                     "%s", "(cc%stride)!=0");
+        return 0;
+    }
+
 	if (cc > stride) {
 		/*
 		 * Pipeline the most common cases.
@@ -321,26 +327,32 @@ horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc)
 			} while (cc>0);
 		}
 	}
+	return 1;
 }
 
-static void
+static int
 swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	uint16* wp = (uint16*) cp0;
 	tmsize_t wc = cc / 2;
 
         TIFFSwabArrayOfShort(wp, wc);
-        horAcc16(tif, cp0, cc);
+        return horAcc16(tif, cp0, cc);
 }
 
-static void
+static int
 horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	tmsize_t stride = PredictorState(tif)->stride;
 	uint16* wp = (uint16*) cp0;
 	tmsize_t wc = cc / 2;
 
-	assert((cc%(2*stride))==0);
+    if((cc%(2*stride))!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "horAcc16",
+                     "%s", "cc%(2*stride))!=0");
+        return 0;
+    }
 
 	if (wc > stride) {
 		wc -= stride;
@@ -349,26 +361,32 @@ horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
 			wc -= stride;
 		} while (wc > 0);
 	}
+	return 1;
 }
 
-static void
+static int
 swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	uint32* wp = (uint32*) cp0;
 	tmsize_t wc = cc / 4;
 
         TIFFSwabArrayOfLong(wp, wc);
-	horAcc32(tif, cp0, cc);
+	return horAcc32(tif, cp0, cc);
 }
 
-static void
+static int
 horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	tmsize_t stride = PredictorState(tif)->stride;
 	uint32* wp = (uint32*) cp0;
 	tmsize_t wc = cc / 4;
 
-	assert((cc%(4*stride))==0);
+    if((cc%(4*stride))!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "horAcc32",
+                     "%s", "cc%(4*stride))!=0");
+        return 0;
+    }
 
 	if (wc > stride) {
 		wc -= stride;
@@ -377,12 +395,13 @@ horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
 			wc -= stride;
 		} while (wc > 0);
 	}
+	return 1;
 }
 
 /*
  * Floating point predictor accumulation routine.
  */
-static void
+static int
 fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	tmsize_t stride = PredictorState(tif)->stride;
@@ -392,10 +411,15 @@ fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc)
 	uint8 *cp = (uint8 *) cp0;
 	uint8 *tmp = (uint8 *)_TIFFmalloc(cc);
 
-	assert((cc%(bps*stride))==0);
+    if(cc%(bps*stride)!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "fpAcc",
+                     "%s", "cc%(bps*stride))!=0");
+        return 0;
+    }
 
 	if (!tmp)
-		return;
+		return 0;
 
 	while (count > stride) {
 		REPEAT4(stride, cp[stride] =
@@ -417,6 +441,7 @@ fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc)
 		}
 	}
 	_TIFFfree(tmp);
+    return 1;
 }
 
 /*
@@ -432,8 +457,7 @@ PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
 	assert(sp->decodepfunc != NULL);  
 
 	if ((*sp->decoderow)(tif, op0, occ0, s)) {
-		(*sp->decodepfunc)(tif, op0, occ0);
-		return 1;
+		return (*sp->decodepfunc)(tif, op0, occ0);
 	} else
 		return 0;
 }
@@ -456,10 +480,16 @@ PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
 	if ((*sp->decodetile)(tif, op0, occ0, s)) {
 		tmsize_t rowsize = sp->rowsize;
 		assert(rowsize > 0);
-		assert((occ0%rowsize)==0);
+		if((occ0%rowsize) !=0)
+        {
+            TIFFErrorExt(tif->tif_clientdata, "PredictorDecodeTile",
+                         "%s", "occ0%rowsize != 0");
+            return 0;
+        }
 		assert(sp->decodepfunc != NULL);
 		while (occ0 > 0) {
-			(*sp->decodepfunc)(tif, op0, rowsize);
+			if( !(*sp->decodepfunc)(tif, op0, rowsize) )
+                return 0;
 			occ0 -= rowsize;
 			op0 += rowsize;
 		}
@@ -468,14 +498,19 @@ PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
 		return 0;
 }
 
-static void
+static int
 horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	TIFFPredictorState* sp = PredictorState(tif);
 	tmsize_t stride = sp->stride;
 	unsigned char* cp = (unsigned char*) cp0;
 
-	assert((cc%stride)==0);
+    if((cc%stride)!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "horDiff8",
+                     "%s", "(cc%stride)!=0");
+        return 0;
+    }
 
 	if (cc > stride) {
 		cc -= stride;
@@ -513,9 +548,10 @@ horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc)
 			} while ((cc -= stride) > 0);
 		}
 	}
+	return 1;
 }
 
-static void
+static int
 horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	TIFFPredictorState* sp = PredictorState(tif);
@@ -523,7 +559,12 @@ horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
 	uint16 *wp = (uint16*) cp0;
 	tmsize_t wc = cc/2;
 
-	assert((cc%(2*stride))==0);
+    if((cc%(2*stride))!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "horDiff8",
+                     "%s", "(cc%(2*stride))!=0");
+        return 0;
+    }
 
 	if (wc > stride) {
 		wc -= stride;
@@ -533,20 +574,23 @@ horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
 			wc -= stride;
 		} while (wc > 0);
 	}
+	return 1;
 }
 
-static void
+static int
 swabHorDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
     uint16* wp = (uint16*) cp0;
     tmsize_t wc = cc / 2;
 
-    horDiff16(tif, cp0, cc);
+    if( !horDiff16(tif, cp0, cc) )
+        return 0;
 
     TIFFSwabArrayOfShort(wp, wc);
+    return 1;
 }
 
-static void
+static int
 horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	TIFFPredictorState* sp = PredictorState(tif);
@@ -554,7 +598,12 @@ horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
 	uint32 *wp = (uint32*) cp0;
 	tmsize_t wc = cc/4;
 
-	assert((cc%(4*stride))==0);
+    if((cc%(4*stride))!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "horDiff32",
+                     "%s", "(cc%(4*stride))!=0");
+        return 0;
+    }
 
 	if (wc > stride) {
 		wc -= stride;
@@ -564,23 +613,26 @@ horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
 			wc -= stride;
 		} while (wc > 0);
 	}
+	return 1;
 }
 
-static void
+static int
 swabHorDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
     uint32* wp = (uint32*) cp0;
     tmsize_t wc = cc / 4;
 
-    horDiff32(tif, cp0, cc);
+    if( !horDiff32(tif, cp0, cc) )
+        return 0;
 
     TIFFSwabArrayOfLong(wp, wc);
+    return 1;
 }
 
 /*
  * Floating point predictor differencing routine.
  */
-static void
+static int
 fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc)
 {
 	tmsize_t stride = PredictorState(tif)->stride;
@@ -590,10 +642,14 @@ fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc)
 	uint8 *cp = (uint8 *) cp0;
 	uint8 *tmp = (uint8 *)_TIFFmalloc(cc);
 
-	assert((cc%(bps*stride))==0);
-
+    if((cc%(bps*stride))!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "fpDiff",
+                     "%s", "(cc%(bps*stride))!=0");
+        return 0;
+    }
 	if (!tmp)
-		return;
+		return 0;
 
 	_TIFFmemcpy(tmp, cp0, cc);
 	for (count = 0; count < wc; count++) {
@@ -613,6 +669,7 @@ fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc)
 	cp += cc - stride - 1;
 	for (count = cc; count > stride; count -= stride)
 		REPEAT4(stride, cp[stride] = (unsigned char)((cp[stride] - cp[0])&0xff); cp--)
+    return 1;
 }
 
 static int
@@ -625,7 +682,8 @@ PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
 	assert(sp->encoderow != NULL);
 
 	/* XXX horizontal differencing alters user's data XXX */
-	(*sp->encodepfunc)(tif, bp, cc);
+	if( !(*sp->encodepfunc)(tif, bp, cc) )
+        return 0;
 	return (*sp->encoderow)(tif, bp, cc, s);
 }
 
@@ -660,7 +718,12 @@ PredictorEncodeTile(TIFF* tif, uint8* bp0, tmsize_t cc0, uint16 s)
 
 	rowsize = sp->rowsize;
 	assert(rowsize > 0);
-	assert((cc0%rowsize)==0);
+	if((cc0%rowsize)!=0)
+    {
+        TIFFErrorExt(tif->tif_clientdata, "PredictorEncodeTile",
+                     "%s", "(cc0%rowsize)!=0");
+        return 0;
+    }
 	while (cc > 0) {
 		(*sp->encodepfunc)(tif, bp, rowsize);
 		cc -= rowsize;
diff --git a/libtiff/tif_predict.h b/libtiff/tif_predict.h
index dc7144c6..6c68e21a 100644
--- a/libtiff/tif_predict.h
+++ b/libtiff/tif_predict.h
@@ -1,4 +1,4 @@
-/* $Id: tif_predict.h,v 1.8 2010-03-10 18:56:49 bfriesen Exp $ */
+/* $Id: tif_predict.h,v 1.9 2016-10-31 17:24:26 erouault Exp $ */
 
 /*
  * Copyright (c) 1995-1997 Sam Leffler
@@ -30,6 +30,8 @@
  * ``Library-private'' Support for the Predictor Tag
  */
 
+typedef int (*TIFFEncodeDecodeMethod)(TIFF* tif, uint8* buf, tmsize_t size);
+
 /*
  * Codecs that want to support the Predictor tag must place
  * this structure first in their private state block so that
@@ -43,12 +45,12 @@ typedef struct {
 	TIFFCodeMethod  encoderow;	/* parent codec encode/decode row */
 	TIFFCodeMethod  encodestrip;	/* parent codec encode/decode strip */
 	TIFFCodeMethod  encodetile;	/* parent codec encode/decode tile */ 
-	TIFFPostMethod  encodepfunc;	/* horizontal differencer */
+	TIFFEncodeDecodeMethod  encodepfunc;	/* horizontal differencer */
 
 	TIFFCodeMethod  decoderow;	/* parent codec encode/decode row */
 	TIFFCodeMethod  decodestrip;	/* parent codec encode/decode strip */
 	TIFFCodeMethod  decodetile;	/* parent codec encode/decode tile */ 
-	TIFFPostMethod  decodepfunc;	/* horizontal accumulator */
+	TIFFEncodeDecodeMethod  decodepfunc;	/* horizontal accumulator */
 
 	TIFFVGetMethod  vgetparent;	/* super-class method */
 	TIFFVSetMethod  vsetparent;	/* super-class method */