ghostscript: fix CVE-2023-29979

Backport from 10.02.0 (unreleased).

Signed-off-by: Joe Slater <joe.slater@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 61 insertions, 0 deletions

diff --git a/meta/recipes-extended/ghostscript/ghostscript/cve-2023-28879.patch b/meta/recipes-extended/ghostscript/ghostscript/cve-2023-28879.patch
new file mode 100644
index 0000000000..9b057d609a
--- /dev/null
+++ b/meta/recipes-extended/ghostscript/ghostscript/cve-2023-28879.patch
@@ -0,0 +1,60 @@
+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.
+---
+CVE: CVE-2023-28879
+
+Upstream-Status: Backport [see text]
+
+git://git.ghostscript.com/ghostpdl
+cherry-pick
+
+Signed-off-by: Joe Slater <joe.slater@windriver.com>
+
+---
+ 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;
+-- 
+2.25.1
+
diff --git a/meta/recipes-extended/ghostscript/ghostscript_9.55.0.bb b/meta/recipes-extended/ghostscript/ghostscript_9.55.0.bb
index 365420fb64..f29c57beea 100644
--- a/meta/recipes-extended/ghostscript/ghostscript_9.55.0.bb
+++ b/meta/recipes-extended/ghostscript/ghostscript_9.55.0.bb
@@ -34,6 +34,7 @@ SRC_URI_BASE = "https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/d
                 file://avoid-host-contamination.patch \
                 file://mkdir-p.patch \
                 file://CVE-2022-2085.patch \
+                file://cve-2023-28879.patch \
 "
 
 SRC_URI = "${SRC_URI_BASE} \