svn commit: r299495 - head/crypto/heimdal/lib/krb5

[Conrad E. Meyer]

Author: cem
Date: Wed May 11 23:25:59 2016
New Revision: 299495
URL: https://svnweb.freebsd.org/changeset/base/299495

Log:
  libkrb5: Fix potential double-free
  
  If krb5_make_principal fails, tmp_creds.server may remain a pointer to freed
  memory and then be double-freed.  After freeing it the first time, initialize
  it to NULL, which causes subsequent krb5_free_principal calls to do the right
  thing.
  
  Reported by:	Coverity
  CID:		1273430
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/crypto/heimdal/lib/krb5/get_cred.c

Modified: head/crypto/heimdal/lib/krb5/get_cred.c
==============================================================================
--- head/crypto/heimdal/lib/krb5/get_cred.c	Wed May 11 23:16:11 2016	(r299494)
+++ head/crypto/heimdal/lib/krb5/get_cred.c	Wed May 11 23:25:59 2016	(r299495)
@@ -831,6 +831,7 @@ get_cred_kdc_capath_worker(krb5_context 
 	if(strcmp(tgt_inst, server_realm) == 0)
 	    break;
 	krb5_free_principal(context, tmp_creds.server);
+	tmp_creds.server = NULL;
 	ret = krb5_make_principal(context, &tmp_creds.server,
 				  tgt_inst, KRB5_TGS_NAME, server_realm, NULL);
 	if(ret) {