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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B166BC433F5 for ; Sat, 5 Mar 2022 20:01:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232272AbiCEUCQ (ORCPT ); Sat, 5 Mar 2022 15:02:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232267AbiCEUCN (ORCPT ); Sat, 5 Mar 2022 15:02:13 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD5DF21B4 for ; Sat, 5 Mar 2022 12:01:22 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 73BE6B80C75 for ; Sat, 5 Mar 2022 20:01:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D70F6C004E1; Sat, 5 Mar 2022 20:01:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646510480; bh=TEY46aM6vt7D+6Se4dcfdpJOlZ0DyWcGNAXL9zE6nfg=; h=Subject:To:Cc:From:Date:From; b=t7XfCUuJ0EvtegruUw4OcSklgeED2oQl1rTuv4WPpZe6nHxCuKGtMm63ID4dX109+ hLTfNDIXjuDZJfDKt8ZepIkqgzc1W/40DXoOjvfg8BF3fhSYYYThqaquvtddAj1gH+ jtK4jPCHiTDIdwqyQHHRBa90mE/CW7/LhvwvVgLg= Subject: FAILED: patch "[PATCH] iavf: Fix locking for VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS" failed to apply to 5.16-stable tree To: slawomirx.laba@intel.com, anthony.l.nguyen@intel.com, jacob.e.keller@intel.com, konrad0.jankowski@intel.com, mateusz.palczewski@intel.com, phani.r.burra@intel.com Cc: From: Date: Sat, 05 Mar 2022 21:01:09 +0100 Message-ID: <16465104691251@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 0579fafd37fb7efe091f0e6c8ccf968864f40f3e Mon Sep 17 00:00:00 2001 From: Slawomir Laba Date: Wed, 23 Feb 2022 13:37:50 +0100 Subject: [PATCH] iavf: Fix locking for VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS iavf_virtchnl_completion is called under crit_lock but when the code for VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS is called, this lock is released in order to obtain rtnl_lock to avoid ABBA deadlock with unregister_netdev. Along with the new way iavf_remove behaves, there exist many risks related to the lock release and attmepts to regrab it. The driver faces crashes related to races between unregister_netdev and netdev_update_features. Yet another risk is that the driver could already obtain the crit_lock in order to destroy it and iavf_virtchnl_completion could crash or block forever. Make iavf_virtchnl_completion never relock crit_lock in it's call paths. Extract rtnl_lock locking logic to the driver for unregister_netdev in order to set the netdev_registered flag inside the lock. Introduce a new flag that will inform adminq_task to perform the code from VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS right after it finishes processing messages. Guard this code with remove flags so it's never called when the driver is in remove state. Fixes: 5951a2b9812d ("iavf: Fix VLAN feature flags after VFR") Signed-off-by: Slawomir Laba Signed-off-by: Phani Burra Signed-off-by: Jacob Keller Signed-off-by: Mateusz Palczewski Tested-by: Konrad Jankowski Signed-off-by: Tony Nguyen diff --git a/drivers/net/ethernet/intel/iavf/iavf.h b/drivers/net/ethernet/intel/iavf/iavf.h index f259fd517b2c..89423947ee65 100644 --- a/drivers/net/ethernet/intel/iavf/iavf.h +++ b/drivers/net/ethernet/intel/iavf/iavf.h @@ -287,6 +287,7 @@ struct iavf_adapter { #define IAVF_FLAG_LEGACY_RX BIT(15) #define IAVF_FLAG_REINIT_ITR_NEEDED BIT(16) #define IAVF_FLAG_QUEUES_DISABLED BIT(17) +#define IAVF_FLAG_SETUP_NETDEV_FEATURES BIT(18) /* duplicates for common code */ #define IAVF_FLAG_DCB_ENABLED 0 /* flags for admin queue service task */ diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c index be51da978e7c..67349d24dc90 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -2879,6 +2879,24 @@ static void iavf_adminq_task(struct work_struct *work) } while (pending); mutex_unlock(&adapter->crit_lock); + if ((adapter->flags & IAVF_FLAG_SETUP_NETDEV_FEATURES)) { + if (adapter->netdev_registered || + !test_bit(__IAVF_IN_REMOVE_TASK, &adapter->crit_section)) { + struct net_device *netdev = adapter->netdev; + + rtnl_lock(); + netdev_update_features(netdev); + rtnl_unlock(); + /* Request VLAN offload settings */ + if (VLAN_V2_ALLOWED(adapter)) + iavf_set_vlan_offload_features + (adapter, 0, netdev->features); + + iavf_set_queue_vlan_tag_loc(adapter); + } + + adapter->flags &= ~IAVF_FLAG_SETUP_NETDEV_FEATURES; + } if ((adapter->flags & (IAVF_FLAG_RESET_PENDING | IAVF_FLAG_RESET_NEEDED)) || adapter->state == __IAVF_RESETTING) @@ -4606,8 +4624,10 @@ static void iavf_remove(struct pci_dev *pdev) cancel_delayed_work_sync(&adapter->watchdog_task); if (adapter->netdev_registered) { - unregister_netdev(netdev); + rtnl_lock(); + unregister_netdevice(netdev); adapter->netdev_registered = false; + rtnl_unlock(); } if (CLIENT_ALLOWED(adapter)) { err = iavf_lan_del_device(adapter); diff --git a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c index 5ee1d118fd30..88844d68e150 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c +++ b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c @@ -2146,29 +2146,7 @@ void iavf_virtchnl_completion(struct iavf_adapter *adapter, sizeof(adapter->vlan_v2_caps))); iavf_process_config(adapter); - - /* unlock crit_lock before acquiring rtnl_lock as other - * processes holding rtnl_lock could be waiting for the same - * crit_lock - */ - mutex_unlock(&adapter->crit_lock); - /* VLAN capabilities can change during VFR, so make sure to - * update the netdev features with the new capabilities - */ - rtnl_lock(); - netdev_update_features(netdev); - rtnl_unlock(); - if (iavf_lock_timeout(&adapter->crit_lock, 10000)) - dev_warn(&adapter->pdev->dev, "failed to acquire crit_lock in %s\n", - __FUNCTION__); - - /* Request VLAN offload settings */ - if (VLAN_V2_ALLOWED(adapter)) - iavf_set_vlan_offload_features(adapter, 0, - netdev->features); - - iavf_set_queue_vlan_tag_loc(adapter); - + adapter->flags |= IAVF_FLAG_SETUP_NETDEV_FEATURES; } break; case VIRTCHNL_OP_ENABLE_QUEUES: