From patchwork Wed May 19 06:05:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saeed Mahameed X-Patchwork-Id: 443083 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 3545AC433ED for ; Wed, 19 May 2021 06:06:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13C05613AF for ; Wed, 19 May 2021 06:06:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239263AbhESGHg (ORCPT ); Wed, 19 May 2021 02:07:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:49244 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236973AbhESGHZ (ORCPT ); Wed, 19 May 2021 02:07:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B0F53613AD; Wed, 19 May 2021 06:06:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621404366; bh=obzuLFR2aFgEoxCAuKHqAPaDVlVIDoK/xSaVj5RW/8k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KRn0UhCkXRYaPR0GMTwPmmspLMXpfzvyngk/Y351OK7sqvormEafx8dtDN8fxzLQl eU0Vih+8ph4SbQimtie4AiZh/2TO+tduGOM+VGjWFeYy152A5ali6iF+8dz/cviimF bG1usgn+TcUUrMHUqIz+6+t2CpI87wgW+PjuqqaFA2c7mBhX8ewb0xC1e8nIWTHU7u BIcPbcXJHAUGNxJpG3HZ6cHU5Or3HkCbIqvYeV7m8vQFr07QPryPuNKu+EQ7/iPT+4 ypYVAB9VIW5waEY5gVcnV8ccFBDYOz0EPk/mniHT9s+Z5X6KPuiD35JVQNLIEXwyn3 wDRcL9+U561mg== From: Saeed Mahameed To: "David S. Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Tariq Toukan , Leon Romanovsky , Dima Chumak , Vlad Buslov , Saeed Mahameed Subject: [net 02/16] net/mlx5e: Fix nullptr in add_vlan_push_action() Date: Tue, 18 May 2021 23:05:09 -0700 Message-Id: <20210519060523.17875-3-saeed@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210519060523.17875-1-saeed@kernel.org> References: <20210519060523.17875-1-saeed@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Dima Chumak The result of dev_get_by_index_rcu() is not checked for NULL and then gets dereferenced immediately. Also, the RCU lock must be held by the caller of dev_get_by_index_rcu(), which isn't satisfied by the call stack. Fix by handling nullptr return value when iflink device is not found. Add RCU locking around dev_get_by_index_rcu() to avoid possible adverse effects while iterating over the net_device's hlist. It is safe not to increment reference count of the net_device pointer in case of a successful lookup, because it's already handled by VLAN code during VLAN device registration (see register_vlan_dev and netdev_upper_dev_link). Fixes: 278748a95aa3 ("net/mlx5e: Offload TC e-switch rules with egress VLAN device") Addresses-Coverity: ("Dereference null return value") Signed-off-by: Dima Chumak Reviewed-by: Vlad Buslov Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c index 47a9c49b25fd..46945d04b5b8 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -3526,8 +3526,12 @@ static int add_vlan_push_action(struct mlx5e_priv *priv, if (err) return err; - *out_dev = dev_get_by_index_rcu(dev_net(vlan_dev), - dev_get_iflink(vlan_dev)); + rcu_read_lock(); + *out_dev = dev_get_by_index_rcu(dev_net(vlan_dev), dev_get_iflink(vlan_dev)); + rcu_read_unlock(); + if (!*out_dev) + return -ENODEV; + if (is_vlan_dev(*out_dev)) err = add_vlan_push_action(priv, attr, out_dev, action);