[gimp] Bug 790853 - (CVE-2017-17787) heap overread in psp importer.

[Jehan Pagès <jehanp src gnome org>]

commit eb2980683e6472aff35a3117587c4f814515c74d
Author: Jehan <jehan girinstud io>
Date:   Thu Dec 21 12:49:41 2017 +0100

    Bug 790853 - (CVE-2017-17787) heap overread in psp importer.
    
    As any external data, we have to check that strings being read at fixed
    length are properly nul-terminated.

 plug-ins/common/file-psp.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/plug-ins/common/file-psp.c b/plug-ins/common/file-psp.c
index c25bece..8e0517c 100644
--- a/plug-ins/common/file-psp.c
+++ b/plug-ins/common/file-psp.c
@@ -893,6 +893,12 @@ read_creator_block (FILE     *f,
               g_free (string);
               return -1;
             }
+          if (string[length - 1] != '\0')
+            {
+              g_message ("Creator keyword data not nul-terminated");
+              g_free (string);
+              return -1;
+            }
           switch (keyword)
             {
             case PSP_CRTR_FLD_TITLE: