On Sun, Apr 11, 2021 at 12:23 AM <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > 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 <stable@xxxxxxxxxxxxxxx>. I sent a patch that should resolve the conflict for 4.19 and 5.4. https://lore.kernel.org/lkml/20210412180907.1980874-1-saravanak@xxxxxxxxxx/T/#u -Saravana > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From eed6e41813deb9ee622cd9242341f21430d7789f Mon Sep 17 00:00:00 2001 > From: Saravana Kannan <saravanak@xxxxxxxxxx> > 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: stable@xxxxxxxxxxxxxxx > Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") > Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> > Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@xxxxxxxxxx > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index e2cf3b29123e..37a5e5f8b221 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -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); >
