[glib/wip/3v1n0/regex-pcre2-flags-fixes: 5/11] gregex: Fix a potential PCRE2 code leak on reallocation failures

[Marco Trevisan <marcotrevi src gnome org>]

commit 1b9689149ca4da096497e8ef51c31147e6eac273
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Tue Sep 6 17:20:45 2022 +0200

    gregex: Fix a potential PCRE2 code leak on reallocation failures
    
    In case recalc_match_offsets() failed we were just returning, but in
    such case, per the documentation we should still set the match_info (if
    provided) and free the pcre2 code instance.
    
    So let's just break the loop we're in it, as if we we've no matches set.
    This also avoids re-allocating the offsets array and potentially
    accessing to unset data.

 glib/gregex.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)
---
diff --git a/glib/gregex.c b/glib/gregex.c
index f2a5b5fd1c..6f3ee88122 100644
--- a/glib/gregex.c
+++ b/glib/gregex.c
@@ -2337,13 +2337,6 @@ g_regex_match_all_full (const GRegex      *regex,
                                        info->match_data,
                                        info->match_context,
                                        info->workspace, info->n_workspace);
-
-      if (!recalc_match_offsets (info, error))
-        {
-          g_match_info_free (info);
-          return FALSE;
-        }
-
       if (info->matches == PCRE2_ERROR_DFA_WSSIZE)
         {
           /* info->workspace is too small. */
@@ -2370,6 +2363,11 @@ g_regex_match_all_full (const GRegex      *regex,
                        _("Error while matching regular expression %s: %s"),
                        regex->pattern, match_error (info->matches));
         }
+      else if (info->matches > 0)
+        {
+          if (!recalc_match_offsets (info, error))
+            info->matches = PCRE2_ERROR_NOMATCH;
+        }
     }
 
   pcre2_code_free (pcre_re);