From 4e851d1391f56c632c271fd21dd96f29565cadfe Mon Sep 17 00:00:00 2001
From: Sumit Bose <sbose@redhat.com>
Date: Tue, 22 May 2018 18:03:05 +0200
Subject: [PATCH] krb5 locator: make plugin more robust

Although currently libkrb5 sets all parameters of the locator plugin
calls to suitable values we should make sure that provided pointers are
not NULL before trying to dereference them.

Related to https://pagure.io/SSSD/sssd/issue/941
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

(cherry picked from commit c1fbc6b64ecaf51efc4379c4c8a4960de095abf0)
---
 src/krb5_plugin/sssd_krb5_locator_plugin.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/krb5_plugin/sssd_krb5_locator_plugin.c b/src/krb5_plugin/sssd_krb5_locator_plugin.c
index 58cac7f4b244903347e6f1811cd8de2d61281c4f..9874fd2d1ce63b69099f057dd05f6e353a12ce75 100644
--- a/src/krb5_plugin/sssd_krb5_locator_plugin.c
+++ b/src/krb5_plugin/sssd_krb5_locator_plugin.c
@@ -439,6 +439,10 @@ krb5_error_code sssd_krb5_locator_lookup(void *private_data,
     if (private_data == NULL) return KRB5_PLUGIN_NO_HANDLE;
     ctx = (struct sssd_ctx *) private_data;
 
+    if (realm == NULL || cbfunc == NULL || cbdata == NULL) {
+        return KRB5_PLUGIN_NO_HANDLE;
+    }
+
     if (ctx->disabled) {
         PLUGIN_DEBUG(("Plugin disabled, nothing to do.\n"));
         return KRB5_PLUGIN_NO_HANDLE;
-- 
2.17.1