From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:34952 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726338AbgCHPBK (ORCPT ); Sun, 8 Mar 2020 11:01:10 -0400 Date: Sun, 8 Mar 2020 17:01:07 +0200 From: Leon Romanovsky Subject: Re: [PATCH net] net/smc: cancel event worker during device removal Message-ID: <20200308150107.GC11496@unreal> References: <20200306134518.84416-1-kgraul@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200306134518.84416-1-kgraul@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Karsten Graul Cc: davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, heiko.carstens@de.ibm.com, raspl@linux.ibm.com, ubraun@linux.ibm.com On Fri, Mar 06, 2020 at 02:45:18PM +0100, Karsten Graul wrote: > During IB device removal, cancel the event worker before the device > structure is freed. In the worker, check if the device is being > terminated and do not proceed with the event work in that case. > > Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client") > Reported-by: syzbot+b297c6825752e7a07272@syzkaller.appspotmail.com > Signed-off-by: Karsten Graul > Reviewed-by: Ursula Braun > --- > net/smc/smc_ib.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c > index d6ba186f67e2..5e4e64a9aa4b 100644 > --- a/net/smc/smc_ib.c > +++ b/net/smc/smc_ib.c > @@ -240,6 +240,9 @@ static void smc_ib_port_event_work(struct work_struct *work) > work, struct smc_ib_device, port_event_work); > u8 port_idx; > > + if (list_empty(&smcibdev->list)) > + return; > + How can it be true if you are not holding "smc_ib_devices.lock" during execution of smc_ib_port_event_work()? > for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) { > smc_ib_remember_port_attr(smcibdev, port_idx + 1); > clear_bit(port_idx, &smcibdev->port_event_mask); > @@ -582,6 +585,7 @@ static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data) > smc_smcr_terminate_all(smcibdev); > smc_ib_cleanup_per_ibdev(smcibdev); > ib_unregister_event_handler(&smcibdev->event_handler); > + cancel_work_sync(&smcibdev->port_event_work); > kfree(smcibdev); > } > > -- > 2.17.1 >