gnu: libxfont: Fix CVE-2017-13720, CVE-2017-13722.

* gnu/packages/patches/libxfont-CVE-2017-13720.patch,
  gnu/packages/patches/libxfont-CVE-2017-13722.patch: New files.
* gnu/local.mk (dist_patch_DATA): Register them.
* gnu/packages/xorg.scm (libxfont, libxfont2)[source]: Use them.

gnu/local.mk

@@ -818,6 +818,8 @@ dist_patch_DATA =						\
   %D%/packages/patches/libvisio-fix-tests.patch			\
   %D%/packages/patches/libvpx-CVE-2016-2818.patch		\
   %D%/packages/patches/libxcb-python-3.5-compat.patch		\
+  %D%/packages/patches/libxfont-CVE-2017-13720.patch		\
+  %D%/packages/patches/libxfont-CVE-2017-13722.patch		\
   %D%/packages/patches/libxml2-CVE-2016-4658.patch		\
   %D%/packages/patches/libxml2-CVE-2016-5131.patch		\
   %D%/packages/patches/libxml2-CVE-2017-0663.patch		\

gnu/packages/patches/libxfont-CVE-2017-13720.patch

@@ -0,0 +1,36 @@
+Fix CVE-2017-13720.
+
+Copied from upstream source repository:
+<https://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=d1e670a4a8704b8708e493ab6155589bcd570608>
+
+
+From d1e670a4a8704b8708e493ab6155589bcd570608 Mon Sep 17 00:00:00 2001
+From: Michal Srb <msrb@suse.com>
+Date: Thu, 20 Jul 2017 13:38:53 +0200
+Subject: Check for end of string in PatternMatch (CVE-2017-13720)
+
+If a pattern contains '?' character, any character in the string is skipped,
+even if it is '\0'. The rest of the matching then reads invalid memory.
+
+Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
+Signed-off-by: Julien Cristau <jcristau@debian.org>
+
+diff --git a/src/fontfile/fontdir.c b/src/fontfile/fontdir.c
+index 4ce2473..996b7d1 100644
+--- a/src/fontfile/fontdir.c
++++ b/src/fontfile/fontdir.c
+@@ -400,8 +400,10 @@ PatternMatch(char *pat, int patdashes, char *string, int stringdashes)
+ 		}
+ 	    }
+ 	case '?':
+-	    if (*string++ == XK_minus)
++	    if ((t = *string++) == XK_minus)
+ 		stringdashes--;
++	    if (!t)
++		return 0;
+ 	    break;
+ 	case '\0':
+ 	    return (*string == '\0');
+-- 
+cgit v0.10.2
+

gnu/packages/patches/libxfont-CVE-2017-13722.patch

@@ -0,0 +1,53 @@
+Fix CVE-2017-13722.
+
+Copied from upstream source repository:
+<https://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=672bb944311392e2415b39c0d63b1e1902905bcd>
+
+From 672bb944311392e2415b39c0d63b1e1902905bcd Mon Sep 17 00:00:00 2001
+From: Michal Srb <msrb@suse.com>
+Date: Thu, 20 Jul 2017 17:05:23 +0200
+Subject: pcfGetProperties: Check string boundaries (CVE-2017-13722)
+
+Without the checks a malformed PCF file can cause the library to make
+atom from random heap memory that was behind the `strings` buffer.
+This may crash the process or leak information.
+
+Signed-off-by: Julien Cristau <jcristau@debian.org>
+
+diff --git a/src/bitmap/pcfread.c b/src/bitmap/pcfread.c
+index dab1c44..ae34c28 100644
+--- a/src/bitmap/pcfread.c
++++ b/src/bitmap/pcfread.c
+@@ -45,6 +45,7 @@ from The Open Group.
+ 
+ #include <stdarg.h>
+ #include <stdint.h>
++#include <string.h>
+ 
+ void
+ pcfError(const char* message, ...)
+@@ -311,11 +312,19 @@ pcfGetProperties(FontInfoPtr pFontInfo, FontFilePtr file,
+     if (IS_EOF(file)) goto Bail;
+     position += string_size;
+     for (i = 0; i < nprops; i++) {
++	if (props[i].name >= string_size) {
++	    pcfError("pcfGetProperties(): String starts out of bounds (%ld/%d)\n", props[i].name, string_size);
++	    goto Bail;
++	}
+ 	props[i].name = MakeAtom(strings + props[i].name,
+-				 strlen(strings + props[i].name), TRUE);
++				 strnlen(strings + props[i].name, string_size - props[i].name), TRUE);
+ 	if (isStringProp[i]) {
++	    if (props[i].value >= string_size) {
++		pcfError("pcfGetProperties(): String starts out of bounds (%ld/%d)\n", props[i].value, string_size);
++		goto Bail;
++	    }
+ 	    props[i].value = MakeAtom(strings + props[i].value,
+-				      strlen(strings + props[i].value), TRUE);
++				      strnlen(strings + props[i].value, string_size - props[i].value), TRUE);
+ 	}
+     }
+     free(strings);
+-- 
+cgit v0.10.2
+

gnu/packages/xorg.scm

@@ -4862,6 +4862,8 @@ an X Window System display.")
                "mirror://xorg/individual/lib/libXfont-"
                version
                ".tar.bz2"))
+        (patches (search-patches "libxfont-CVE-2017-13720.patch"
+                                 "libxfont-CVE-2017-13722.patch"))
         (sha256
           (base32
             "0w8d07bkmjiarkx09579bl8zsq903mn8javc7qpi0ix4ink5x502"))))
@@ -4895,6 +4897,8 @@ new API's in libXft, or the legacy API's in libX11.")
               (method url-fetch)
               (uri (string-append "mirror://xorg/individual/lib/libXfont2-"
                                   version ".tar.bz2"))
+              (patches (search-patches "libxfont-CVE-2017-13720.patch"
+                                       "libxfont-CVE-2017-13722.patch"))
               (sha256
                (base32
                 "0znvwk36nhmyqpmhbm9mzisgixp1mp5qkfald8x1n5yxbm3vpyz9"))))))