fix CVE-2023-28879

CVE-2023-28879.patch

@@ -0,0 +1,41 @@
+From 6d6fae79e016629b6c896463f62e7b1a6e651ed6 Mon Sep 17 00:00:00 2001
+From: liningjie <liningjie@xfusion.com>
+Date: Thu, 24 Aug 2023 11:36:22 +0800
+Subject: [PATCH] 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 | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/base/sbcp.c b/base/sbcp.c
+index 6b0383c..3b8970f 100644
+--- a/base/sbcp.c
++++ b/base/sbcp.c
+@@ -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;
+-- 
+2.27.0

ghostscript.spec

@@ -9,7 +9,7 @@
 
 Name:             ghostscript
 Version:          9.52
-Release:          8
+Release:          9
 Summary:          An interpreter for PostScript and PDF files
 License:          AGPLv3+
 URL:              https://ghostscript.com/
@@ -50,6 +50,7 @@ Patch31: backport-Fix-pdfwrite-d-mode-with-file-permissions.patch
 Patch32: backport-Coverity-361429-move-break-to-correct-place.patch
 Patch33: backport-CVE-2021-3781-BUg-704342-Include-device-specifier-strings-in-acces.patch
 Patch34: CVE-2023-38559.patch
+Patch35: CVE-2023-28879.patch
 
 BuildRequires:    automake gcc
 BuildRequires:    adobe-mappings-cmap-devel adobe-mappings-pdf-devel
@@ -210,6 +211,9 @@ install -m 0755 -d %{buildroot}%{_datadir}/%{name}/conf.d/
 %{_bindir}/dvipdf
 
 %changelog
+* Thu Aug 24 2023 liningjie <liningjie@xfusion.com> - 9.52-9
+- fix CVE-2023-28879
+
 * Tue Aug 15 2023 liningjie <liningjie@xfusion.com> - 9.52-8
 - Type:CVE
 - ID:CVE-2023-38559