From nobody Tue Sep 16 23:55:20 2025 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 C4D9AC4167B for ; Mon, 26 Dec 2022 18:11:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232039AbiLZSLS (ORCPT ); Mon, 26 Dec 2022 13:11:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229614AbiLZSLO (ORCPT ); Mon, 26 Dec 2022 13:11:14 -0500 X-Greylist: delayed 63 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 26 Dec 2022 10:11:10 PST Received: from exchange.fintech.ru (e10edge.fintech.ru [195.54.195.159]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 308C0333; Mon, 26 Dec 2022 10:11:10 -0800 (PST) Received: from Ex16-01.fintech.ru (10.0.10.18) by exchange.fintech.ru (195.54.195.169) with Microsoft SMTP Server (TLS) id 14.3.498.0; Mon, 26 Dec 2022 21:10:01 +0300 Received: from localhost (10.0.253.157) by Ex16-01.fintech.ru (10.0.10.18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Mon, 26 Dec 2022 21:10:01 +0300 From: Nikita Zhandarovich To: , Greg Kroah-Hartman CC: Nikita Zhandarovich , =?UTF-8?q?Dima=C2=B7Chumak=C2=B7?= , Saeed Mahameed , Leon Romanovsky , "David S. Miller" , Jakub Kicinski , , , , , Vlad Buslov Subject: [PATCH 5.10 1/1] net/mlx5e: Fix nullptr in mlx5e_tc_add_fdb_flow() Date: Mon, 26 Dec 2022 10:09:50 -0800 Message-ID: <20221226180950.86129-2-n.zhandarovich@fintech.ru> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221226180950.86129-1-n.zhandarovich@fintech.ru> References: <20221226180950.86129-1-n.zhandarovich@fintech.ru> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.0.253.157] X-ClientProxiedBy: Ex16-01.fintech.ru (10.0.10.18) To Ex16-01.fintech.ru (10.0.10.18) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Dima Chumak commit fe7738eb3ca3631a75844e790f6cb576c0fe7b00 upstream. The result of __dev_get_by_index() is not checked for NULL, which then passed to mlx5e_attach_encap() and gets dereferenced. Also, in case of a successful lookup, the net_device reference count is not incremented, which may result in net_device pointer becoming invalid at any time during mlx5e_attach_encap() execution. Fix by using dev_get_by_index(), which does proper reference counting on the net_device pointer. Also, handle nullptr return value when mirred device is not found. It's safe to call dev_put() on the mirred net_device pointer, right after mlx5e_attach_encap() call, because it's not being saved/copied down the call chain. Fixes: 3c37745ec614 ("net/mlx5e: Properly deal with encap flows add/del und= er neigh update") Addresses-Coverity: ("Dereference null return value") Signed-off-by: Dima Chumak Reviewed-by: Vlad Buslov Signed-off-by: Saeed Mahameed Signed-off-by: Nikita Zhandarovich --- drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/= ethernet/mellanox/mlx5/core/en_tc.c index ce710f22b1ff..fbfce2b3baeb 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -1307,9 +1307,9 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv, struct netlink_ext_ack *extack) { struct mlx5_eswitch *esw =3D priv->mdev->priv.eswitch; - struct net_device *out_dev, *encap_dev =3D NULL; struct mlx5e_tc_flow_parse_attr *parse_attr; struct mlx5_flow_attr *attr =3D flow->attr; + struct net_device *encap_dev =3D NULL; struct mlx5_esw_flow_attr *esw_attr; struct mlx5_fc *counter =3D NULL; struct mlx5e_rep_priv *rpriv; @@ -1354,16 +1354,22 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv, esw_attr =3D attr->esw_attr; =20 for (out_index =3D 0; out_index < MLX5_MAX_FLOW_FWD_VPORTS; out_index++) { + struct net_device *out_dev; int mirred_ifindex; =20 if (!(esw_attr->dests[out_index].flags & MLX5_ESW_DEST_ENCAP)) continue; =20 mirred_ifindex =3D parse_attr->mirred_ifindex[out_index]; - out_dev =3D __dev_get_by_index(dev_net(priv->netdev), - mirred_ifindex); + out_dev =3D dev_get_by_index(dev_net(priv->netdev), mirred_ifindex); + if (!out_dev) { + NL_SET_ERR_MSG_MOD(extack, "Requested mirred device not found"); + err =3D -ENODEV; + return err; + } err =3D mlx5e_attach_encap(priv, flow, out_dev, out_index, extack, &encap_dev, &encap_valid); + dev_put(out_dev); if (err) return err; =20 --=20 2.25.1