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Commit f59a6ec2 authored by Saravana Kannan's avatar Saravana Kannan Committed by Greg Kroah-Hartman
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driver core: Fix locking bug in deferred_probe_timeout_work_func() 



commit eed6e41813deb9ee622cd9242341f21430d7789f upstream.

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: stable@vger.kernel.org
Fixes: 25b4e70d ("driver core: allow stopping deferred probe after init")
Signed-off-by: default avatarSaravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 12ec8025

drivers/base/dd.c

+5 −3
Original line number Diff line number Diff line
@@ -254,14 +254,16 @@ 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;



	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");

	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);

}

static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);