File CVE-2017-7207.patch of Package ghostscript.4931

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File CVE-2017-7207.patch of Package ghostscript.4931

From 309eca4e0a31ea70dcc844812691439312dad091 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.
---
 base/gdevmem.c | 2 ++
 1 file changed, 2 insertions(+)

Index: ghostscript-9.15/base/gdevmem.c
===================================================================
--- ghostscript-9.15.orig/base/gdevmem.c	2014-09-22 12:17:33.000000000 +0200
+++ ghostscript-9.15/base/gdevmem.c	2017-04-28 10:55:17.479490151 +0200
@@ -590,6 +590,8 @@ mem_get_bits_rectangle(gx_device * dev,
             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);

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File CVE-2017-7207.patch of Package ghostscript.4931

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