[Fwd: Re: malloc bugs]

[Will Ballantyne <Will.Ballantyne@gems1.gov.bc.ca>]

I should have sent this to devel instead of replying...

-------- Original Message --------
Subject: Re: malloc bugs
Date: Mon, 23 Nov 1998 17:23:25 +0000
From: Will Ballantyne <Will.Ballantyne@gems1.gov.bc.ca>
Organization: ITSD
To: openldap-bugs@openldap.org
References: <HBF.981123gq8j@bombur2.uio.no>


Hallvard B Furuseth wrote:
> 
> derefDN() in servers/slapd/back-ldbm/alias.c is broken:
>   It may free() `dn' (and maybe other variables) without resetting them,
>   and they wil then be used later (e.g. dn is used after the for loop).
>   Nor am I sure what it is supposed to return in all cases, or whether
>   or not it is always supposed to return newly allocated data.

Thanks Hallvard, here is a quick patch to fix.  It should always return newly
allocated data.

diff -ur ldap/servers/slapd/back-ldbm/alias.c
ldap.new/servers/slapd/back-ldbm/alias.c
--- ldap/servers/slapd/back-ldbm/alias.c        Wed Nov  4 20:05:05 1998
+++ ldap.new/servers/slapd/back-ldbm/alias.c    Mon Nov 23 09:08:54 1998
@@ -112,8 +112,8 @@
 )
 {
   struct ldbminfo *li = (struct ldbminfo *) be->be_private;
-  char         *matched;
-  char         *newDN;
+  char         *matched = 0;
+  char         *newDN = NULL;
   int  depth;
   Entry        *eMatched;
   Entry        *eDeref;
@@ -156,6 +156,7 @@
        if ((eNew = derefAlias_r( be, conn, op, eMatched )) == NULL) {
          free (matched);
          free (newDN);
+         newDN = NULL;
          free (remainder);
          break; /*  no associated entry, dont deref */
        }
@@ -166,6 +167,7 @@
          if (!strcasecmp (matched, eNew->e_dn)) {
            /* newDN same as old so not an alias, no need to go further */
            free (newDN);
+            newDN = NULL;
            free (matched);
            free (remainder);
            break;
@@ -226,9 +228,12 @@
     send_ldap_result( conn, op, LDAP_ALIAS_PROBLEM, "",
                      "Maximum alias dereference depth exceeded for base" );
   }
+
+  if (newDN == NULL) {
+    newDN = strdup ( dn );
+  }
   
   Debug( LDAP_DEBUG_TRACE, "<= returning deref DN of  %s\n", newDN, 0, 0 ); 
-
   free(matched);
 
   return newDN;