ghostscript: CVE-2017-7207

The mem_get_bits_rectangle function in Artifex Software, Inc.
Ghostscript 9.20 allows remote attackers to cause a denial
of service (NULL pointer dereference) via a crafted PostScript
document.

Reference:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-7207

Upstream patch:
http://git.ghostscript.com/?p=ghostpdl.git;h=309eca4e0a31ea70dcc844812691439312dad091

(From OE-Core rev: 0f22a27c2abd2f2dd9119681f139dd85dcb6479d)

Signed-off-by: Catalin Enache <catalin.enache@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/ghostscript/ghostscript/CVE-2017-7207.patch

@@ -0,0 +1,39 @@
+From 0e88bee1304993668fede72498d656a2dd33a35e Mon Sep 17 00:00:00 2001
+From: Ken Sharp <ken.sharp@artifex.com>
+Date: Mon, 20 Mar 2017 09:34:11 +0000
+Subject: [PATCH] Ensure a device has raster memory, before trying to read it.
+
+Bug #697676 "Null pointer dereference in mem_get_bits_rectangle()"
+
+This is only possible by abusing/mis-using Ghostscript-specific
+language extensions, so cannot happen in a general PostScript program.
+
+Nevertheless, Ghostscript should not crash. So this commit checks the
+memory device to see if raster memory has been allocated, before trying
+to read from it.
+
+Upstream-Status: Backport
+CVE: CVE-2017-7207
+
+Author: Ken Sharp <ken.sharp@artifex.com>
+Signed-off-by: Catalin Enache <catalin.enache@windriver.com>
+---
+ base/gdevmem.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/base/gdevmem.c b/base/gdevmem.c
+index 41108ba..183f96d 100644
+--- a/base/gdevmem.c
++++ b/base/gdevmem.c
+@@ -605,6 +605,8 @@ mem_get_bits_rectangle(gx_device * dev, const gs_int_rect * prect,
+             GB_PACKING_CHUNKY | GB_COLORS_NATIVE | GB_ALPHA_NONE;
+         return_error(gs_error_rangecheck);
+     }
++    if (mdev->line_ptrs == 0x00)
++        return_error(gs_error_rangecheck);
+     if ((w <= 0) | (h <= 0)) {
+         if ((w | h) < 0)
+             return_error(gs_error_rangecheck);
+-- 
+2.10.2
+

meta/recipes-extended/ghostscript/ghostscript_9.20.bb

@@ -31,6 +31,7 @@ SRC_URI = "${SRC_URI_BASE} \
            file://ghostscript-9.02-genarch.patch \
            file://objarch.h \
            file://cups-no-gcrypt.patch \
+           file://CVE-2017-7207.patch \
            "
 
 SRC_URI_class-native = "${SRC_URI_BASE} \