From: Xin Long <lucien....@gmail.com>
Date: Sat, 10 Jun 2017 14:48:14 +0800
> Now sctp holds read_lock when foreach sctp_ep_hashtable without disabling
> BH. If CPU schedules to another thread A at this moment, the thread A may
> be trying to hold the write_lock with disabling BH.
>
> As BH is disabled and CPU cannot schedule back to the thread holding the
> read_lock, while the thread A keeps waiting for the read_lock. A dead
> lock would be triggered by this.
>
> This patch is to fix this dead lock by calling read_lock_bh instead to
> disable BH when holding the read_lock in sctp_for_each_endpoint.
>
> Fixes: 626d16f50f39 ("sctp: export some apis or variables for sctp_diag and
> reuse some for proc")
> Reported-by: Xiumei Mu <x...@redhat.com>
> Signed-off-by: Xin Long <lucien....@gmail.com>
Applied and queued up for -stable, thanks.
