Apply security fixes to libtiff that are not in 4.0.6.

third_party/libtiff/0004-CVE-2015-8784.patch

Index: third_party/libtiff/0004-CVE-2015-8784.patch
diff --git a/third_party/libtiff/0004-CVE-2015-8784.patch b/third_party/libtiff/0004-CVE-2015-8784.patch
new file mode 100644
index 0000000000000000000000000000000000000000..e4415de6c1a919fb9259e799b69c64ca69ade152
--- /dev/null
+++ b/third_party/libtiff/0004-CVE-2015-8784.patch
@@ -0,0 +1,50 @@
+From b18012dae552f85dcc5c57d3bf4e997a15b1cc1c Mon Sep 17 00:00:00 2001
+From: erouault <erouault>
+Date: Sun, 27 Dec 2015 16:55:20 +0000
+Subject: [PATCH] * libtiff/tif_next.c: fix potential out-of-bound write in
+ NeXTDecode() triggered by http://lcamtuf.coredump.cx/afl/vulns/libtiff5.tif
+ (bugzilla #2508)
+
+---
+ ChangeLog          |  6 ++++++
+ libtiff/tif_next.c | 10 ++++++++--
+ 2 files changed, 14 insertions(+), 2 deletions(-)
+
+diff --git a/libtiff/tif_next.c b/libtiff/tif_next.c
+index dd669cc..0a5b635 100644
+--- a/libtiff/tif_next.c
++++ b/libtiff/tif_next.c
+@@ -37,7 +37,7 @@
+ 	case 0:	op[0]  = (unsigned char) ((v) << 6); break;	\
+ 	case 1:	op[0] |= (v) << 4; break;	\
+ 	case 2:	op[0] |= (v) << 2; break;	\
+-	case 3:	*op++ |= (v);	   break;	\
++	case 3:	*op++ |= (v);	   op_offset++; break;	\
+ 	}					\
+ }
+ 
+@@ -106,6 +106,7 @@ NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s)
+ 			uint32 imagewidth = tif->tif_dir.td_imagewidth;
+             if( isTiled(tif) )
+                 imagewidth = tif->tif_dir.td_tilewidth;
++            tmsize_t op_offset = 0;
+ 
+ 			/*
+ 			 * The scanline is composed of a sequence of constant
+@@ -122,10 +123,15 @@ NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s)
+ 				 * bounds, potentially resulting in a security
+ 				 * issue.
+ 				 */
+-				while (n-- > 0 && npixels < imagewidth)
++				while (n-- > 0 && npixels < imagewidth && op_offset < scanline)
+ 					SETPIXEL(op, grey);
+ 				if (npixels >= imagewidth)
+ 					break;
++                if (op_offset >= scanline ) {
++                    TIFFErrorExt(tif->tif_clientdata, module, "Invalid data for scanline %ld",
++                        (long) tif->tif_row);
++                    return (0);
++                }
+ 				if (cc == 0)
+ 					goto bad;
+ 				n = *bp++, cc--;