FAILED: patch "[PATCH] driver core: Fix locking bug in" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From eed6e41813deb9ee622cd9242341f21430d7789f Mon Sep 17 00:00:00 2001
From: Saravana Kannan <[email protected]>
Date: Thu, 1 Apr 2021 21:03:40 -0700
Subject: [PATCH] driver core: Fix locking bug in
deferred_probe_timeout_work_func()

list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list.

Cc [email protected]

Fixes 25b4e70dcce9 ("driver core: allow stopping deferred probe after init")

Signed-off-by Saravana Kannan <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Greg Kroah-Hartman <[email protected]>

drivers/base/dd.c +5 -3

index e2cf3b29123e..37a5e5f8b221 100644
@@ -292,14 +292,16 @@ int driver_deferred_probe_check_state(struct device *dev)
 
 static void deferred_probe_timeout_work_func(struct work_struct *work)
 {
-       struct device_private *private, *p;
+       struct device_private *p;
 
        driver_deferred_probe_timeout = 0;
        driver_deferred_probe_trigger();
        flush_work(&deferred_probe_work);
 
-       list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe)
-               dev_info(private->device, "deferred probe pending\n");
+       mutex_lock(&deferred_probe_mutex);
+       list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe)
+               dev_info(p->device, "deferred probe pending\n");
+       mutex_unlock(&deferred_probe_mutex);
        wake_up_all(&probe_timeout_waitqueue);
 }
 static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);