svn rev #25369: branches/krb5-1-9/src/plugins/kdb/ db2/ ldap/libkdb_ldap/

[tlyu@MIT.EDU]

http://src.mit.edu/fisheye/changelog/krb5/?cs=25369
Commit By: tlyu
Log Message:
ticket: 6982
subject: SA-2011-006 KDC denial of service [CVE-2011-1527 CVE-2011-1528 CVE-2011-1529]
version_fixed: 1.9.2
status: resolved

Fix null pointer dereference and assertion failure conditions that
could cause a denial of service.


Changed Files:
U   branches/krb5-1-9/src/plugins/kdb/db2/lockout.c
U   branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c
U   branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/lockout.c
Modified: branches/krb5-1-9/src/plugins/kdb/db2/lockout.c
===================================================================
--- branches/krb5-1-9/src/plugins/kdb/db2/lockout.c	2011-10-18 18:51:35 UTC (rev 25368)
+++ branches/krb5-1-9/src/plugins/kdb/db2/lockout.c	2011-10-18 18:52:37 UTC (rev 25369)
@@ -169,6 +169,9 @@
         return 0;
     }
 
+    if (entry == NULL)
+        return 0;
+
     if (!db_ctx->disable_lockout) {
         code = lookup_lockout_policy(context, entry, &max_fail,
                                      &failcnt_interval, &lockout_duration);
@@ -176,6 +179,15 @@
             return code;
     }
 
+    /*
+     * Don't continue to modify the DB for an already locked account.
+     * (In most cases, status will be KRB5KDC_ERR_CLIENT_REVOKED, and
+     * this check is unneeded, but in rare cases, we can fail with an
+     * integrity error or preauth failure before a policy check.)
+     */
+    if (locked_check_p(context, stamp, max_fail, lockout_duration, entry))
+        return 0;
+
     /* Only mark the authentication as successful if the entry
      * required preauthentication, otherwise we have no idea. */
     if (status == 0 && (entry->attributes & KRB5_KDB_REQUIRES_PRE_AUTH)) {

Modified: branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c
===================================================================
--- branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c	2011-10-18 18:51:35 UTC (rev 25368)
+++ branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c	2011-10-18 18:52:37 UTC (rev 25369)
@@ -105,6 +105,7 @@
     CHECK_LDAP_HANDLE(ldap_context);
 
     if (is_principal_in_realm(ldap_context, searchfor) != 0) {
+        st = KRB5_KDB_NOENTRY;
         krb5_set_error_message (context, st, "Principal does not belong to realm");
         goto cleanup;
     }

Modified: branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/lockout.c
===================================================================
--- branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/lockout.c	2011-10-18 18:51:35 UTC (rev 25368)
+++ branches/krb5-1-9/src/plugins/kdb/ldap/libkdb_ldap/lockout.c	2011-10-18 18:52:37 UTC (rev 25369)
@@ -165,6 +165,9 @@
         return 0;
     }
 
+    if (entry == NULL)
+        return 0;
+
     if (!ldap_context->disable_lockout) {
         code = lookup_lockout_policy(context, entry, &max_fail,
                                      &failcnt_interval,
@@ -173,10 +176,17 @@
             return code;
     }
 
+    /*
+     * Don't continue to modify the DB for an already locked account.
+     * (In most cases, status will be KRB5KDC_ERR_CLIENT_REVOKED, and
+     * this check is unneeded, but in rare cases, we can fail with an
+     * integrity error or preauth failure before a policy check.)
+     */
+    if (locked_check_p(context, stamp, max_fail, lockout_duration, entry))
+        return 0;
+
     entry->mask = 0;
 
-    assert (!locked_check_p(context, stamp, max_fail, lockout_duration, entry));
-
     /* Only mark the authentication as successful if the entry
      * required preauthentication, otherwise we have no idea. */
     if (status == 0 && (entry->attributes & KRB5_KDB_REQUIRES_PRE_AUTH)) {