gnu: libtiff: Fix CVE-2018-{8905,10963}.

* gnu/packages/patches/libtiff-CVE-2018-8905.patch,
gnu/packages/patches/libtiff-CVE-2018-10963.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/image.scm (libtiff)[replacement]: New field.
(libtiff/fixed): New variable.

gnu/local.mk

@@ -887,6 +887,8 @@ dist_patch_DATA =						\
   %D%/packages/patches/libtheora-config-guess.patch		\
   %D%/packages/patches/libtiff-CVE-2017-9935.patch		\
   %D%/packages/patches/libtiff-CVE-2017-18013.patch		\
+  %D%/packages/patches/libtiff-CVE-2018-8905.patch		\
+  %D%/packages/patches/libtiff-CVE-2018-10963.patch		\
   %D%/packages/patches/libtool-skip-tests2.patch		\
   %D%/packages/patches/libusb-0.1-disable-tests.patch		\
   %D%/packages/patches/libusb-for-axoloti.patch			\

gnu/packages/image.scm

@@ -394,6 +394,7 @@ extracting icontainer icon files.")
 (define-public libtiff
   (package
    (name "libtiff")
+   (replacement libtiff/fixed)
    (version "4.0.9")
    (source
      (origin
@@ -426,6 +427,17 @@ collection of tools for doing simple manipulations of TIFF images.")
                                   "See COPYRIGHT in the distribution."))
    (home-page "http://www.simplesystems.org/libtiff/")))
 
+(define libtiff/fixed
+  (package
+    (inherit libtiff)
+    (source
+      (origin
+        (inherit (package-source libtiff))
+        (patches
+          (append (origin-patches (package-source libtiff))
+                  (search-patches "libtiff-CVE-2018-8905.patch"
+                                  "libtiff-CVE-2018-10963.patch")))))))
+
 (define-public leptonica
   (package
     (name "leptonica")

gnu/packages/patches/libtiff-CVE-2018-10963.patch

@@ -0,0 +1,40 @@
+Fix CVE-2018-10963:
+
+http://bugzilla.maptools.org/show_bug.cgi?id=2795
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-10963
+
+Patch copied from upstream source repository:
+
+https://gitlab.com/libtiff/libtiff/commit/de144fd228e4be8aa484c3caf3d814b6fa88c6d9
+
+From de144fd228e4be8aa484c3caf3d814b6fa88c6d9 Mon Sep 17 00:00:00 2001
+From: Even Rouault <even.rouault@spatialys.com>
+Date: Sat, 12 May 2018 14:24:15 +0200
+Subject: [PATCH] TIFFWriteDirectorySec: avoid assertion. Fixes
+ http://bugzilla.maptools.org/show_bug.cgi?id=2795. CVE-2018-10963
+
+---
+ libtiff/tif_dirwrite.c | 7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+diff --git a/libtiff/tif_dirwrite.c b/libtiff/tif_dirwrite.c
+index 2430de6d..c15a28db 100644
+--- a/libtiff/tif_dirwrite.c
++++ b/libtiff/tif_dirwrite.c
+@@ -695,8 +695,11 @@ TIFFWriteDirectorySec(TIFF* tif, int isimage, int imagedone, uint64* pdiroff)
+ 								}
+ 								break;
+ 							default:
+-								assert(0);   /* we should never get here */
+-								break;
++								TIFFErrorExt(tif->tif_clientdata,module,
++								            "Cannot write tag %d (%s)",
++								            TIFFFieldTag(o),
++                                                                            o->field_name ? o->field_name : "unknown");
++								goto bad;
+ 						}
+ 					}
+ 				}
+-- 
+2.17.0
+

gnu/packages/patches/libtiff-CVE-2018-8905.patch

@@ -0,0 +1,61 @@
+Fix CVE-2018-8095:
+
+http://bugzilla.maptools.org/show_bug.cgi?id=2780
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-8905
+
+Patch copied from upstream source repository:
+
+https://gitlab.com/libtiff/libtiff/commit/58a898cb4459055bb488ca815c23b880c242a27d
+
+From 58a898cb4459055bb488ca815c23b880c242a27d Mon Sep 17 00:00:00 2001
+From: Even Rouault <even.rouault@spatialys.com>
+Date: Sat, 12 May 2018 15:32:31 +0200
+Subject: [PATCH] LZWDecodeCompat(): fix potential index-out-of-bounds write.
+ Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2780 / CVE-2018-8905
+
+The fix consists in using the similar code LZWDecode() to validate we
+don't write outside of the output buffer.
+---
+ libtiff/tif_lzw.c | 18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
+
+diff --git a/libtiff/tif_lzw.c b/libtiff/tif_lzw.c
+index 4ccb443c..94d85e38 100644
+--- a/libtiff/tif_lzw.c
++++ b/libtiff/tif_lzw.c
+@@ -602,6 +602,7 @@ LZWDecodeCompat(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
+ 	char *tp;
+ 	unsigned char *bp;
+ 	int code, nbits;
++	int len;
+ 	long nextbits, nextdata, nbitsmask;
+ 	code_t *codep, *free_entp, *maxcodep, *oldcodep;
+ 
+@@ -753,13 +754,18 @@ LZWDecodeCompat(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
+ 				}  while (--occ);
+ 				break;
+ 			}
+-			assert(occ >= codep->length);
+-			op += codep->length;
+-			occ -= codep->length;
+-			tp = op;
++			len = codep->length;
++			tp = op + len;
+ 			do {
+-				*--tp = codep->value;
+-			} while( (codep = codep->next) != NULL );
++				int t;
++				--tp;
++				t = codep->value;
++				codep = codep->next;
++				*tp = (char)t;
++			} while (codep && tp > op);
++			assert(occ >= len);
++			op += len;
++			occ -= len;
+ 		} else {
+ 			*op++ = (char)code;
+ 			occ--;
+-- 
+2.17.0
+