From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Assmann Date: Wed, 21 Aug 2019 16:09:29 +0200 Subject: [Intel-wired-lan] [PATCH] i40e: check __I40E_VF_DISABLE bit in i40e_sync_filters_subtask Message-ID: <20190821140929.26985-1-sassmann@kpanic.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: While testing VF spawn/destroy the following panic occured. BUG: unable to handle kernel NULL pointer dereference at 0000000000000029 [...] Workqueue: i40e i40e_service_task [i40e] RIP: 0010:i40e_sync_vsi_filters+0x6fd/0xc60 [i40e] [...] Call Trace: ? __switch_to_asm+0x35/0x70 ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x35/0x70 ? _cond_resched+0x15/0x30 i40e_sync_filters_subtask+0x56/0x70 [i40e] i40e_service_task+0x382/0x11b0 [i40e] ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x41/0x70 process_one_work+0x1a7/0x3b0 worker_thread+0x30/0x390 ? create_worker+0x1a0/0x1a0 kthread+0x112/0x130 ? kthread_bind+0x30/0x30 ret_from_fork+0x35/0x40 Investigation revealed a race where pf->vf[vsi->vf_id].trusted may get accessed by the watchdog via i40e_sync_filters_subtask() although i40e_free_vfs() already free'd pf->vf. To avoid this the call to i40e_sync_vsi_filters() in i40e_sync_filters_subtask() needs to be guarded by __I40E_VF_DISABLE, which is also used by i40e_free_vfs(). Note: put the __I40E_VF_DISABLE check after the __I40E_MACVLAN_SYNC_PENDING check as the latter is more likely to trigger. Signed-off-by: Stefan Assmann --- drivers/net/ethernet/intel/i40e/i40e_main.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 6d456e579314..f25c7da59b2b 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -2587,6 +2587,10 @@ static void i40e_sync_filters_subtask(struct i40e_pf *pf) return; if (!test_and_clear_bit(__I40E_MACVLAN_SYNC_PENDING, pf->state)) return; + if (test_and_set_bit(__I40E_VF_DISABLE, pf->state)) { + set_bit(__I40E_MACVLAN_SYNC_PENDING, pf->state); + return; + } for (v = 0; v < pf->num_alloc_vsi; v++) { if (pf->vsi[v] && @@ -2601,6 +2605,7 @@ static void i40e_sync_filters_subtask(struct i40e_pf *pf) } } } + clear_bit(__I40E_VF_DISABLE, pf->state); } /** -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22886C3A59E for ; Wed, 21 Aug 2019 14:09:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E03DE2339E for ; Wed, 21 Aug 2019 14:09:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728978AbfHUOJt (ORCPT ); Wed, 21 Aug 2019 10:09:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47670 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728567AbfHUOJs (ORCPT ); Wed, 21 Aug 2019 10:09:48 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4622E3083391; Wed, 21 Aug 2019 14:09:48 +0000 (UTC) Received: from p50.redhat.com (ovpn-117-124.ams2.redhat.com [10.36.117.124]) by smtp.corp.redhat.com (Postfix) with ESMTP id C83F810013A1; Wed, 21 Aug 2019 14:09:46 +0000 (UTC) From: Stefan Assmann To: intel-wired-lan@lists.osuosl.org Cc: netdev@vger.kernel.org, davem@davemloft.net, jeffrey.t.kirsher@intel.com, lihong.yang@intel.com, sassmann@kpanic.de Subject: [PATCH] i40e: check __I40E_VF_DISABLE bit in i40e_sync_filters_subtask Date: Wed, 21 Aug 2019 16:09:29 +0200 Message-Id: <20190821140929.26985-1-sassmann@kpanic.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Wed, 21 Aug 2019 14:09:48 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While testing VF spawn/destroy the following panic occured. BUG: unable to handle kernel NULL pointer dereference at 0000000000000029 [...] Workqueue: i40e i40e_service_task [i40e] RIP: 0010:i40e_sync_vsi_filters+0x6fd/0xc60 [i40e] [...] Call Trace: ? __switch_to_asm+0x35/0x70 ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x35/0x70 ? _cond_resched+0x15/0x30 i40e_sync_filters_subtask+0x56/0x70 [i40e] i40e_service_task+0x382/0x11b0 [i40e] ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x41/0x70 process_one_work+0x1a7/0x3b0 worker_thread+0x30/0x390 ? create_worker+0x1a0/0x1a0 kthread+0x112/0x130 ? kthread_bind+0x30/0x30 ret_from_fork+0x35/0x40 Investigation revealed a race where pf->vf[vsi->vf_id].trusted may get accessed by the watchdog via i40e_sync_filters_subtask() although i40e_free_vfs() already free'd pf->vf. To avoid this the call to i40e_sync_vsi_filters() in i40e_sync_filters_subtask() needs to be guarded by __I40E_VF_DISABLE, which is also used by i40e_free_vfs(). Note: put the __I40E_VF_DISABLE check after the __I40E_MACVLAN_SYNC_PENDING check as the latter is more likely to trigger. Signed-off-by: Stefan Assmann --- drivers/net/ethernet/intel/i40e/i40e_main.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 6d456e579314..f25c7da59b2b 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -2587,6 +2587,10 @@ static void i40e_sync_filters_subtask(struct i40e_pf *pf) return; if (!test_and_clear_bit(__I40E_MACVLAN_SYNC_PENDING, pf->state)) return; + if (test_and_set_bit(__I40E_VF_DISABLE, pf->state)) { + set_bit(__I40E_MACVLAN_SYNC_PENDING, pf->state); + return; + } for (v = 0; v < pf->num_alloc_vsi; v++) { if (pf->vsi[v] && @@ -2601,6 +2605,7 @@ static void i40e_sync_filters_subtask(struct i40e_pf *pf) } } } + clear_bit(__I40E_VF_DISABLE, pf->state); } /** -- 2.21.0