ghostscript: Fix CVE-2023-28879

Upstream-Status: Backport [https://git.ghostscript.com/?p=ghostpdl.git;h=37ed5022cecd584de868933b5b60da2e995b3179]

(From OE-Core rev: ec0c6f941826903b763be76c450f1d4e0e67908e)

Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-extended/ghostscript/ghostscript/CVE-2023-28879.patch

@@ -0,0 +1,54 @@
+From 37ed5022cecd584de868933b5b60da2e995b3179 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.
+
+Upstream-Status: Backport [https://git.ghostscript.com/?p=ghostpdl.git;h=37ed5022cecd584de868933b5b60da2e995b3179]
+CVE: CVE-2023-28879
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ base/sbcp.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/base/sbcp.c b/base/sbcp.c
+index 6b0383c..90784b5 100644
+--- a/base/sbcp.c
++++ b/base/sbcp.c
+@@ -1,4 +1,4 @@
+-/* Copyright (C) 2001-2019 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;
+-- 
+2.25.1
+

meta/recipes-extended/ghostscript/ghostscript_9.52.bb

@@ -39,6 +39,7 @@ SRC_URI_BASE = "https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/d
                 file://CVE-2021-3781_1.patch \
                 file://CVE-2021-3781_2.patch \
                 file://CVE-2021-3781_3.patch \
+                file://CVE-2023-28879.patch \
 "
 
 SRC_URI = "${SRC_URI_BASE} \