fix CVE-2023-28879

(cherry picked from commit 0db73b54a7ff85c6cc304b71d80c268f9e66e441)

CVE-2023-28879.patch

@@ -0,0 +1,49 @@
+From 5fc0b03188397142c61437e8ec68eb947abebf58 Mon Sep 17 00:00:00 2001
+From: Ken Sharp <ken.sharp@artifex.com>
+Date: Fri, 24 Mar 2023 13:19:57 +0000
+Subject: [PATCH] Graphics library - prevent buffer overrun in (T)BCP encoding
+
+Bug #706494 "Buffer Overflow in s_xBCPE_process"
+
+As described in detail in the bug report, if the write buffer is filled
+to one byte less than full, and we then try to write an escaped
+character, we overrun the buffer because we don't check before
+writing two bytes to it.
+
+This just checks if we have two bytes before starting to write an
+escaped character and exits if we don't (replacing the consumed byte
+of the input).
+
+Up for further discussion; why do we even permit a BCP encoding filter
+anyway ? I think we should remove this, at least when SAFER is true.
+---
+ base/sbcp.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/base/sbcp.c b/base/sbcp.c
+index 979ae0992..47fc233ec 100644
+--- a/base/sbcp.c
++++ b/base/sbcp.c
+@@ -1,4 +1,4 @@
+-/* Copyright (C) 2001-2021 Artifex Software, Inc.
++/* Copyright (C) 2001-2023 Artifex Software, Inc.
+    All Rights Reserved.
+ 
+    This software is provided AS-IS with no warranty, either express or
+@@ -50,6 +50,14 @@ s_xBCPE_process(stream_state * st, stream_cursor_read * pr,
+         byte ch = *++p;
+ 
+         if (ch <= 31 && escaped[ch]) {
++            /* Make sure we have space to store two characters in the write buffer,
++             * if we don't then exit without consuming the input character, we'll process
++             * that on the next time round.
++             */
++            if (pw->limit - q < 2) {
++                p--;
++                break;
++            }
+             if (p == rlimit) {
+                 p--;
+                 break;
+-- 
+2.34.1

ghostscript.spec

@@ -9,7 +9,7 @@
 
 Name:             ghostscript
 Version:          9.55.0
-Release:          3
+Release:          4
 Summary:          An interpreter for PostScript and PDF files
 License:          AGPLv3+
 URL:              https://ghostscript.com/
@@ -19,6 +19,7 @@ Patch0:  ghostscript-9.23-100-run-dvipdf-securely.patch
 Patch1:  backport-Bug-704405-Fix-typo-in-non-forked-lcms2-code.patch
 Patch2:  backport-CVE-2022-2085.patch
 Patch3:  CVE-2023-38559.patch
+Patch4:  CVE-2023-28879.patch
 
 BuildRequires:    automake gcc
 BuildRequires:    adobe-mappings-cmap-devel adobe-mappings-pdf-devel
@@ -179,6 +180,9 @@ install -m 0755 -d %{buildroot}%{_datadir}/%{name}/conf.d/
 %{_bindir}/dvipdf
 
 %changelog
+* Thu Aug 24 2023 liningjie <liningjie@xfusion.com> - 9.55.0-4
+- fix CVE-2023-28879
+
 * Tue Aug 15 2023 liningjie <liningjie@xfusion.com> - 9.55.0-3
 - fix CVE-2023-38559