diff --git a/libtiff/tif_getimage.c b/libtiff/tif_getimage.c
index 09eb4a2d..c6041f67 100644
--- a/libtiff/tif_getimage.c
+++ b/libtiff/tif_getimage.c
@@ -1,4 +1,4 @@
-/* $Id: tif_getimage.c,v 1.109 2017-06-30 13:11:18 erouault Exp $ */
+/* $Id: tif_getimage.c,v 1.110 2017-07-04 13:28:42 erouault Exp $ */
 
 /*
  * Copyright (c) 1991-1997 Sam Leffler
@@ -626,7 +626,7 @@ gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
     uint32 col, row, y, rowstoread;
     tmsize_t pos;
     uint32 tw, th;
-    unsigned char* buf;
+    unsigned char* buf = NULL;
     int32 fromskew, toskew;
     uint32 nrow;
     int ret = 1, flip;
@@ -634,13 +634,14 @@ gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
     int32 this_toskew, leftmost_toskew;
     int32 leftmost_fromskew;
     uint32 leftmost_tw;
+    tmsize_t bufsize;
 
-    buf = (unsigned char*) _TIFFmalloc(TIFFTileSize(tif));
-    if (buf == 0) {
-		TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "No space for tile buffer");
-		return (0);
+    bufsize = TIFFTileSize(tif);
+    if (bufsize == 0) {
+        TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "No space for tile buffer");
+        return (0);
     }
-    _TIFFmemset(buf, 0, TIFFTileSize(tif));
+
     TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tw);
     TIFFGetField(tif, TIFFTAG_TILELENGTH, &th);
 
@@ -671,8 +672,9 @@ gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
 	col = img->col_offset;
 	while (tocol < w)
         {
-	    if (TIFFReadTile(tif, buf, col,  
-			     row+img->row_offset, 0, 0)==(tmsize_t)(-1) && img->stoponerr)
+	    if (_TIFFReadTileAndAllocBuffer(tif, (void**) &buf, bufsize, col,
+			     row+img->row_offset, 0, 0)==(tmsize_t)(-1) &&
+                (buf == NULL || img->stoponerr))
             {
                 ret = 0;
                 break;
@@ -737,11 +739,11 @@ gtTileSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
 	uint32 col, row, y, rowstoread;
 	tmsize_t pos;
 	uint32 tw, th;
-	unsigned char* buf;
-	unsigned char* p0;
-	unsigned char* p1;
-	unsigned char* p2;
-	unsigned char* pa;
+	unsigned char* buf = NULL;
+	unsigned char* p0 = NULL;
+	unsigned char* p1 = NULL;
+	unsigned char* p2 = NULL;
+	unsigned char* pa = NULL;
 	tmsize_t tilesize;
 	tmsize_t bufsize;
 	int32 fromskew, toskew;
@@ -760,16 +762,7 @@ gtTileSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
 		TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "Integer overflow in %s", "gtTileSeparate");
 		return (0);
 	}
-	buf = (unsigned char*) _TIFFmalloc(bufsize);
-	if (buf == 0) {
-		TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "No space for tile buffer");
-		return (0);
-	}
-	_TIFFmemset(buf, 0, bufsize);
-	p0 = buf;
-	p1 = p0 + tilesize;
-	p2 = p1 + tilesize;
-	pa = (alpha?(p2+tilesize):NULL);
+
 	TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tw);
 	TIFFGetField(tif, TIFFTAG_TILELENGTH, &th);
 
@@ -789,7 +782,6 @@ gtTileSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
           case PHOTOMETRIC_MINISBLACK:
           case PHOTOMETRIC_PALETTE:
             colorchannels = 1;
-            p2 = p1 = p0;
             break;
 
           default:
@@ -814,7 +806,30 @@ gtTileSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
 		col = img->col_offset;
 		while (tocol < w)
 		{
-			if (TIFFReadTile(tif, p0, col,  
+                        if( buf == NULL )
+                        {
+                            if (_TIFFReadTileAndAllocBuffer(
+                                    tif, (void**) &buf, bufsize, col,
+                                    row+img->row_offset,0,0)==(tmsize_t)(-1)
+                                && (buf == NULL || img->stoponerr))
+                            {
+                                    ret = 0;
+                                    break;
+                            }
+                            p0 = buf;
+                            if( colorchannels == 1 )
+                            {
+                                p2 = p1 = p0;
+                                pa = (alpha?(p0+3*tilesize):NULL);
+                            }
+                            else
+                            {
+                                p1 = p0 + tilesize;
+                                p2 = p1 + tilesize;
+                                pa = (alpha?(p2+tilesize):NULL);
+                            }
+                        }
+			else if (TIFFReadTile(tif, p0, col,  
 			    row+img->row_offset,0,0)==(tmsize_t)(-1) && img->stoponerr)
 			{
 				ret = 0;
diff --git a/libtiff/tif_read.c b/libtiff/tif_read.c
index 8153746d..eb5b7d5c 100644
--- a/libtiff/tif_read.c
+++ b/libtiff/tif_read.c
@@ -1,4 +1,4 @@
-/* $Id: tif_read.c,v 1.63 2017-07-02 14:13:39 erouault Exp $ */
+/* $Id: tif_read.c,v 1.64 2017-07-04 13:28:42 erouault Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -1014,6 +1014,77 @@ TIFFReadEncodedTile(TIFF* tif, uint32 tile, void* buf, tmsize_t size)
 		return ((tmsize_t)(-1));
 }
 
+/* Variant of TIFFReadTile() that does 
+ * * if *buf == NULL, *buf = _TIFFmalloc(bufsizetoalloc) only after TIFFFillTile() has
+ *   suceeded. This avoid excessive memory allocation in case of truncated
+ *   file.
+ * * calls regular TIFFReadEncodedTile() if *buf != NULL
+ */
+tmsize_t
+_TIFFReadTileAndAllocBuffer(TIFF* tif,
+                            void **buf, tmsize_t bufsizetoalloc,
+                            uint32 x, uint32 y, uint32 z, uint16 s)
+{
+    if (!TIFFCheckRead(tif, 1) || !TIFFCheckTile(tif, x, y, z, s))
+            return ((tmsize_t)(-1));
+    return (_TIFFReadEncodedTileAndAllocBuffer(tif,
+                                               TIFFComputeTile(tif, x, y, z, s),
+                                               buf, bufsizetoalloc,
+                                               (tmsize_t)(-1)));
+}
+
+/* Variant of TIFFReadEncodedTile() that does 
+ * * if *buf == NULL, *buf = _TIFFmalloc(bufsizetoalloc) only after TIFFFillTile() has
+ *   suceeded. This avoid excessive memory allocation in case of truncated
+ *   file.
+ * * calls regular TIFFReadEncodedTile() if *buf != NULL
+ */
+tmsize_t
+_TIFFReadEncodedTileAndAllocBuffer(TIFF* tif, uint32 tile,
+                                    void **buf, tmsize_t bufsizetoalloc,
+                                    tmsize_t size_to_read)
+{
+    static const char module[] = "_TIFFReadEncodedTileAndAllocBuffer";
+    TIFFDirectory *td = &tif->tif_dir;
+    tmsize_t tilesize = tif->tif_tilesize;
+
+    if( *buf != NULL )
+    {
+        return TIFFReadEncodedTile(tif, tile, *buf, size_to_read);
+    }
+
+    if (!TIFFCheckRead(tif, 1))
+            return ((tmsize_t)(-1));
+    if (tile >= td->td_nstrips) {
+            TIFFErrorExt(tif->tif_clientdata, module,
+                "%lu: Tile out of range, max %lu",
+                (unsigned long) tile, (unsigned long) td->td_nstrips);
+            return ((tmsize_t)(-1));
+    }
+
+    if (!TIFFFillTile(tif,tile))
+            return((tmsize_t)(-1));
+
+    *buf = _TIFFmalloc(bufsizetoalloc);
+    if (*buf == NULL) {
+            TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif),
+                         "No space for tile buffer");
+            return((tmsize_t)(-1));
+    }
+    _TIFFmemset(*buf, 0, bufsizetoalloc);
+
+    if (size_to_read == (tmsize_t)(-1))
+        size_to_read = tilesize;
+    else if (size_to_read > tilesize)
+        size_to_read = tilesize;
+    if( (*tif->tif_decodetile)(tif,
+        (uint8*) *buf, size_to_read, (uint16)(tile/td->td_stripsperimage))) {
+        (*tif->tif_postdecode)(tif, (uint8*) *buf, size_to_read);
+        return (size_to_read);
+    } else
+        return ((tmsize_t)(-1));
+}
+
 static tmsize_t
 TIFFReadRawTile1(TIFF* tif, uint32 tile, void* buf, tmsize_t size, const char* module)
 {
diff --git a/libtiff/tiffiop.h b/libtiff/tiffiop.h
index 14e8d0ee..87c7cb08 100644
--- a/libtiff/tiffiop.h
+++ b/libtiff/tiffiop.h
@@ -1,4 +1,4 @@
-/* $Id: tiffiop.h,v 1.93 2017-06-30 13:11:18 erouault Exp $ */
+/* $Id: tiffiop.h,v 1.94 2017-07-04 13:28:42 erouault Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -376,6 +376,14 @@ extern tmsize_t
 _TIFFReadEncodedStripAndAllocBuffer(TIFF* tif, uint32 strip,
                                     void **buf, tmsize_t bufsizetoalloc,
                                     tmsize_t size_to_read);
+extern tmsize_t
+_TIFFReadEncodedTileAndAllocBuffer(TIFF* tif, uint32 tile,
+                                    void **buf, tmsize_t bufsizetoalloc,
+                                    tmsize_t size_to_read);
+extern tmsize_t
+_TIFFReadTileAndAllocBuffer(TIFF* tif,
+                            void **buf, tmsize_t bufsizetoalloc,
+                            uint32 x, uint32 y, uint32 z, uint16 s);
 
 extern int TIFFInitDumpMode(TIFF*, int);
 #ifdef PACKBITS_SUPPORT