From e330568504ec379ea42460d21a2e20b1652d9445 Mon Sep 17 00:00:00 2001
From: Reid Wahl <nrwahl@protonmail.com>
Date: Fri, 14 Jan 2022 01:35:35 -0800
Subject: [PATCH] Fix: fencing: Don't set stonith action to pending if fork
 fails

Currently, we set a stonith action to pending if
services_action_async_fork_notify() returns true. However, "true" means
that the svc_action should not be freed. This might be because the
svc_action forked successfully and is pending, or it might be because
the svc_action has already been freed.

In the case of stonith actions, if we fail to fork, the stonith_action_t
object stored in svc_action->cb_data gets freed by the done callback,
and services_action_async_fork_notify() returns true. If we try to set
the action to pending, it causes a segfault.

This commit moves the "set to pending" step to the
stonith_action_async_forked() callback. We avoid the segfault and only
set it to pending if it's actually pending.

A slight difference in ordering was required to achieve this. Now, the
action gets set to pending immediately before being added to the
mainloop, instead of immediately after.

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>
---
 lib/fencing/st_actions.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/fencing/st_actions.c b/lib/fencing/st_actions.c
index e4e43225cd..306001af69 100644
--- a/lib/fencing/st_actions.c
+++ b/lib/fencing/st_actions.c
@@ -550,6 +550,9 @@ stonith_action_async_forked(svc_action_t *svc_action)
         (action->fork_cb) (svc_action->pid, action->userdata);
     }
 
+    pcmk__set_result(&(action->result), PCMK_OCF_UNKNOWN, PCMK_EXEC_PENDING,
+                     NULL);
+
     crm_trace("Child process %d performing action '%s' successfully forked",
               action->pid, action->action);
 }
@@ -619,8 +622,6 @@ internal_stonith_action_execute(stonith_action_t * action)
         if (services_action_async_fork_notify(svc_action,
                                               &stonith_action_async_done,
                                               &stonith_action_async_forked)) {
-            pcmk__set_result(&(action->result), PCMK_OCF_UNKNOWN,
-                             PCMK_EXEC_PENDING, NULL);
             return pcmk_ok;
         }
 
-- 
2.27.0