From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755384AbcEQBWQ (ORCPT ); Mon, 16 May 2016 21:22:16 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34306 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755106AbcEQBWM (ORCPT ); Mon, 16 May 2016 21:22:12 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maor Gottlieb , Amir Vadai , Saeed Mahameed , "David S. Miller" Subject: [PATCH 4.5 014/101] net/mlx5_core: Fix soft lockup in steering error flow Date: Mon, 16 May 2016 18:20:19 -0700 Message-Id: <20160517011506.878916034@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160517011506.359924439@linuxfoundation.org> References: <20160517011506.359924439@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maor Gottlieb [ Upstream commit c3f9bf628bc7edda298897d952f5e761137229c9 ] In the error flow of adding flow rule to auto-grouped flow table, we call to tree_remove_node. tree_remove_node locks the node's parent, however the node's parent is already locked by mlx5_add_flow_rule and this causes a deadlock. After this patch, if we failed to add the flow rule, we unlock the flow table before calling to tree_remove_node. fixes: f0d22d187473 ('net/mlx5_core: Introduce flow steering autogrouped flow table') Signed-off-by: Maor Gottlieb Reported-by: Amir Vadai Signed-off-by: Saeed Mahameed Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx5/core/fs_core.c | 46 ++++++++-------------- 1 file changed, 17 insertions(+), 29 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c @@ -957,33 +957,6 @@ unlock_fg: return rule; } -static struct mlx5_flow_rule *add_rule_to_auto_fg(struct mlx5_flow_table *ft, - u8 match_criteria_enable, - u32 *match_criteria, - u32 *match_value, - u8 action, - u32 flow_tag, - struct mlx5_flow_destination *dest) -{ - struct mlx5_flow_rule *rule; - struct mlx5_flow_group *g; - - g = create_autogroup(ft, match_criteria_enable, match_criteria); - if (IS_ERR(g)) - return (void *)g; - - rule = add_rule_fg(g, match_value, - action, flow_tag, dest); - if (IS_ERR(rule)) { - /* Remove assumes refcount > 0 and autogroup creates a group - * with a refcount = 0. - */ - tree_get_node(&g->node); - tree_remove_node(&g->node); - } - return rule; -} - struct mlx5_flow_rule * mlx5_add_flow_rule(struct mlx5_flow_table *ft, u8 match_criteria_enable, @@ -1008,8 +981,23 @@ mlx5_add_flow_rule(struct mlx5_flow_tabl goto unlock; } - rule = add_rule_to_auto_fg(ft, match_criteria_enable, match_criteria, - match_value, action, flow_tag, dest); + g = create_autogroup(ft, match_criteria_enable, match_criteria); + if (IS_ERR(g)) { + rule = (void *)g; + goto unlock; + } + + rule = add_rule_fg(g, match_value, + action, flow_tag, dest); + if (IS_ERR(rule)) { + /* Remove assumes refcount > 0 and autogroup creates a group + * with a refcount = 0. + */ + unlock_ref_node(&ft->node); + tree_get_node(&g->node); + tree_remove_node(&g->node); + return rule; + } unlock: unlock_ref_node(&ft->node); return rule;