From patchwork Wed Sep 11 16:50:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirsher, Jeffrey T" X-Patchwork-Id: 1161151 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46T7F965W3z9sNk for ; Thu, 12 Sep 2019 02:50:37 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729490AbfIKQug (ORCPT ); Wed, 11 Sep 2019 12:50:36 -0400 Received: from mga14.intel.com ([192.55.52.115]:31967 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729349AbfIKQuQ (ORCPT ); Wed, 11 Sep 2019 12:50:16 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2019 09:50:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,489,1559545200"; d="scan'208";a="385759041" Received: from jtkirshe-desk1.jf.intel.com ([134.134.177.96]) by fmsmga006.fm.intel.com with ESMTP; 11 Sep 2019 09:50:15 -0700 From: Jeff Kirsher To: davem@davemloft.net Cc: Stefan Assmann , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, stable@vger.kernel.org, Andrew Bowers , Jeff Kirsher Subject: [net-next v2 02/13] i40e: check __I40E_VF_DISABLE bit in i40e_sync_filters_subtask Date: Wed, 11 Sep 2019 09:50:03 -0700 Message-Id: <20190911165014.10742-3-jeffrey.t.kirsher@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190911165014.10742-1-jeffrey.t.kirsher@intel.com> References: <20190911165014.10742-1-jeffrey.t.kirsher@intel.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Stefan Assmann While testing VF spawn/destroy the following panic occurred. 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. CC: stable@vger.kernel.org Signed-off-by: Stefan Assmann Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- 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 e9f2f276bf27..3e2e465f43f9 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -2592,6 +2592,10 @@ 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] && @@ -2606,6 +2610,7 @@ static void i40e_sync_filters_subtask(struct i40e_pf *pf) } } } + clear_bit(__I40E_VF_DISABLE, pf->state); } /**