From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net] net: bpfilter: use get_pid_task instead of pid_task
Date: Wed, 17 Oct 2018 22:04:39 -0700 (PDT)
Message-ID: <20181017.220439.2058059014966719056.davem@davemloft.net>
References: <20181016153510.16962-1-ap420073@gmail.com>
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Cc: netdev@vger.kernel.org, daniel@iogearbox.net, ast@kernel.org
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From: Taehee Yoo <ap420073@gmail.com>
Date: Wed, 17 Oct 2018 00:35:10 +0900

> pid_task() dereferences rcu protected tasks array.
> But there is no rcu_read_lock() in shutdown_umh() routine so that
> rcu_read_lock() is needed.
> get_pid_task() is wrapper function of pid_task. it holds rcu_read_lock()
> then calls pid_task(). if task isn't NULL, it increases reference count
> of task.
> 
> test commands:
>    %modprobe bpfilter
>    %modprobe -rv bpfilter
 ...
> Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module")
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>

Applied and queued up for -stable, thanks.