From: Zdenek Dohnal <zdohnal@redhat.com>
Date: Fri, 24 Nov 2023 10:46:53 +0000 (+0100)
Subject: raster-interpreter.c: Fix crash in 'scan_ps()' found by fuzzer
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F834%2Fhead;p=thirdparty%2Fcups.git

raster-interpreter.c: Fix crash in 'scan_ps()' found by fuzzer

Fuzzer using `_cupsRasterExecPS()` found a way how to pass NULL into
`scan_ps()`, causing crash - we have to sanitize the argument for NULL
to fix it.

Fixes #831
---

diff --git a/cups/raster-interpret.c b/cups/raster-interpret.c
index 4387876bf7..45f2b22427 100644
--- a/cups/raster-interpret.c
+++ b/cups/raster-interpret.c
@@ -1047,6 +1047,8 @@ scan_ps(_cups_ps_stack_t *st,		/* I  - Stack */
   int			parens;		/* Parenthesis nesting level */
 
 
+  if (!*ptr)
+    return (NULL);
  /*
   * Skip leading whitespace...
   */