From cb94d00f31d1d6b6fcaa69dbaa928031d2e7c092 Mon Sep 17 00:00:00 2001
From: Sumit Bose <sbose@redhat.com>
Date: Fri, 24 May 2019 09:18:25 +0200
Subject: [PATCH 28/29] DP: add NULL check to be_ptask_{enable|disable}

Currently the files and the proxy provider do not provide a check online
method (DPM_CHECK_ONLINE). The files provider because it can never go
offline. The proxy provider because there is no generic way to check
since the nature of the actual provider is unknown.

Since the method is missing check_if_online() jumps into the error
handling block were we try to reset the offline state
unconditionally. If there is no check_if_online_ptask, which never
exists for the files provider and will not be available in the proxy
provider as long as the backend is online, be_ptask_{enable|disable}
will be called with a NULL pointer.

Related to https://pagure.io/SSSD/sssd/issue/4014

Reviewed-by: Tomas Halman <thalman@redhat.com>
Reviewed-by: Alexey Tikhonov <atikhono@redhat.com>
(cherry picked from commit 2720d97ce2559a3a382caf8f669820f64d6097fe)
---
 src/providers/be_ptask.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/providers/be_ptask.c b/src/providers/be_ptask.c
index dc3c57db5..c43351755 100644
--- a/src/providers/be_ptask.c
+++ b/src/providers/be_ptask.c
@@ -352,26 +352,31 @@ done:
 
 void be_ptask_enable(struct be_ptask *task)
 {
-    if (task->enabled) {
-        DEBUG(SSSDBG_MINOR_FAILURE, "Task [%s]: already enabled\n",
-                                     task->name);
-        return;
-    }
+    if (task != NULL) {
+        if (task->enabled) {
+            DEBUG(SSSDBG_MINOR_FAILURE, "Task [%s]: already enabled\n",
+                                         task->name);
+            return;
+        }
 
-    DEBUG(SSSDBG_TRACE_FUNC, "Task [%s]: enabling task\n", task->name);
+        DEBUG(SSSDBG_TRACE_FUNC, "Task [%s]: enabling task\n", task->name);
 
-    task->enabled = true;
-    be_ptask_schedule(task, BE_PTASK_ENABLED_DELAY, BE_PTASK_SCHEDULE_FROM_NOW);
+        task->enabled = true;
+        be_ptask_schedule(task, BE_PTASK_ENABLED_DELAY,
+                          BE_PTASK_SCHEDULE_FROM_NOW);
+    }
 }
 
 /* Disable the task, but if a request already in progress, let it finish. */
 void be_ptask_disable(struct be_ptask *task)
 {
-    DEBUG(SSSDBG_TRACE_FUNC, "Task [%s]: disabling task\n", task->name);
+    if (task != NULL) {
+        DEBUG(SSSDBG_TRACE_FUNC, "Task [%s]: disabling task\n", task->name);
 
-    talloc_zfree(task->timer);
-    task->enabled = false;
-    task->period = task->orig_period;
+        talloc_zfree(task->timer);
+        task->enabled = false;
+        task->period = task->orig_period;
+    }
 }
 
 void be_ptask_destroy(struct be_ptask **task)
-- 
2.20.1