From patchwork Tue Jul 27 23:20:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saeed Mahameed X-Patchwork-Id: 487293 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=-19.7 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 069EDC4338F for ; Tue, 27 Jul 2021 23:21:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E476060241 for ; Tue, 27 Jul 2021 23:21:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233733AbhG0XVO (ORCPT ); Tue, 27 Jul 2021 19:21:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:35304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232745AbhG0XU7 (ORCPT ); Tue, 27 Jul 2021 19:20:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 21E9060234; Tue, 27 Jul 2021 23:20:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627428058; bh=Q8FzgYKWOfQFoWOAEx83VIS+OnhbSvtXIs02e9DNYbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iuzSILDl39YVPllm0o0KWm9WslNqBeaukb+0EfhzsqGXkoPXze9QNk7myQ/M2m7j/ ZgJjcDQj7PBnPIoDqW/ATY0/yI/0hkA3Bk2OdGTAa7HYMke7IqdP5PfZNDF67c4eFs f7+ohK4uTnmv6h3dKbohXdjIdzuORdMs1EbYdHFjtibq0FSqHsnB8+Ore3P0lE1kDy V43VT7KMoZDLy6XR1JVMOdUDCEaL68fH4TfjHqTSTq8AyHgeuw7bLFlIPp9zkRaxNE 096AqunTkRIJoBCQHz8MZ76FZkLrSuZFHws8siXQAQFAafG4bKZr/BiV6+dK06GXRI 7NS123YPwT6tQ== From: Saeed Mahameed To: "David S. Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Tariq Toukan , Dima Chumak , Vlad Buslov , Roi Dayan , Saeed Mahameed Subject: [net 11/12] net/mlx5e: Fix nullptr in mlx5e_hairpin_get_mdev() Date: Tue, 27 Jul 2021 16:20:49 -0700 Message-Id: <20210727232050.606896-12-saeed@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210727232050.606896-1-saeed@kernel.org> References: <20210727232050.606896-1-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() is not checked for NULL and then gets dereferenced immediately. Also, __dev_get_by_index() must be called while holding either RTNL lock or @dev_base_lock, which isn't satisfied by mlx5e_hairpin_get_mdev() or its callers. This makes the underlying hlist_for_each_entry() loop not safe, and can have adverse effects in itself. Fix by using dev_get_by_index() and handling nullptr return value when ifindex device is not found. Update mlx5e_hairpin_get_mdev() callers to check for possible PTR_ERR() result. Fixes: 77ab67b7f0f9 ("net/mlx5e: Basic setup of hairpin object") Addresses-Coverity: ("Dereference null return value") Signed-off-by: Dima Chumak Reviewed-by: Vlad Buslov Reviewed-by: Roi Dayan Signed-off-by: Saeed Mahameed --- .../net/ethernet/mellanox/mlx5/core/en_tc.c | 33 +++++++++++++++++-- 1 file changed, 31 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 629a61e8022f..d273758255c3 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -452,12 +452,32 @@ static void mlx5e_detach_mod_hdr(struct mlx5e_priv *priv, static struct mlx5_core_dev *mlx5e_hairpin_get_mdev(struct net *net, int ifindex) { + struct mlx5_core_dev *mdev; struct net_device *netdev; struct mlx5e_priv *priv; - netdev = __dev_get_by_index(net, ifindex); + netdev = dev_get_by_index(net, ifindex); + if (!netdev) + return ERR_PTR(-ENODEV); + priv = netdev_priv(netdev); - return priv->mdev; + mdev = priv->mdev; + dev_put(netdev); + + /* Mirred tc action holds a refcount on the ifindex net_device (see + * net/sched/act_mirred.c:tcf_mirred_get_dev). So, it's okay to continue using mdev + * after dev_put(netdev), while we're in the context of adding a tc flow. + * + * The mdev pointer corresponds to the peer/out net_device of a hairpin. It is then + * stored in a hairpin object, which exists until all flows, that refer to it, get + * removed. + * + * On the other hand, after a hairpin object has been created, the peer net_device may + * be removed/unbound while there are still some hairpin flows that are using it. This + * case is handled by mlx5e_tc_hairpin_update_dead_peer, which is hooked to + * NETDEV_UNREGISTER event of the peer net_device. + */ + return mdev; } static int mlx5e_hairpin_create_transport(struct mlx5e_hairpin *hp) @@ -666,6 +686,10 @@ mlx5e_hairpin_create(struct mlx5e_priv *priv, struct mlx5_hairpin_params *params func_mdev = priv->mdev; peer_mdev = mlx5e_hairpin_get_mdev(dev_net(priv->netdev), peer_ifindex); + if (IS_ERR(peer_mdev)) { + err = PTR_ERR(peer_mdev); + goto create_pair_err; + } pair = mlx5_core_hairpin_create(func_mdev, peer_mdev, params); if (IS_ERR(pair)) { @@ -804,6 +828,11 @@ static int mlx5e_hairpin_flow_add(struct mlx5e_priv *priv, int err; peer_mdev = mlx5e_hairpin_get_mdev(dev_net(priv->netdev), peer_ifindex); + if (IS_ERR(peer_mdev)) { + NL_SET_ERR_MSG_MOD(extack, "invalid ifindex of mirred device"); + return PTR_ERR(peer_mdev); + } + if (!MLX5_CAP_GEN(priv->mdev, hairpin) || !MLX5_CAP_GEN(peer_mdev, hairpin)) { NL_SET_ERR_MSG_MOD(extack, "hairpin is not supported"); return -EOPNOTSUPP;