From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EE15837178 for ; Mon, 16 Oct 2023 20:17:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OD2rfkau" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C4DEC433C9; Mon, 16 Oct 2023 20:17:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697487423; bh=jIMYJZdLSkIjGhV+sa8/zN79aQ1+r4oyWNEsEnAiRtA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OD2rfkauCejGrdo1+gvNdyygx2aTWDd0Niij7iUwY1oR8NDyPuyQtj4RXBHGLtLC9 BLC3LHnb2Ot9Y6/Vhowg5Lu/IE03bQTJ5MChzJBxbVOtBBSM/EXW+KwAvYyEXR3rUX 6lSSiCIBB84p2Lk6rV3aKh9yRVXpdd58ppW3MlO899zo/xqughZexUEWkkcwPtf44U TdSeY/gCjkRGHtAaXV4Hife0wzRnDfuCu7n20oSa3zwYFIHU0F3jiGkE3JDBRLw1r6 2AtxP/VRdpwdwm9EBWZt+hnZKXPtC70ow0Hd1cHCUBJ0gsnE87P+aRj+RmRfRseMeM ZLTfaw3+ltSJQ== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, Jakub Kicinski , gnault@redhat.com, liuhangbin@gmail.com, lucien.xin@gmail.com, jiri@resnulli.us Subject: [PATCH net 2/5] net: check for altname conflicts when changing netdev's netns Date: Mon, 16 Oct 2023 13:16:54 -0700 Message-ID: <20231016201657.1754763-3-kuba@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231016201657.1754763-1-kuba@kernel.org> References: <20231016201657.1754763-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit It's currently possible to create an altname conflicting with an altname or real name of another device by creating it in another netns and moving it over: [ ~]$ ip link add dev eth0 type dummy [ ~]$ ip netns add test [ ~]$ ip -netns test link add dev ethX netns test type dummy [ ~]$ ip -netns test link property add dev ethX altname eth0 [ ~]$ ip -netns test link set dev ethX netns 1 [ ~]$ ip link ... 3: eth0: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 02:40:88:62:ec:b8 brd ff:ff:ff:ff:ff:ff ... 5: ethX: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 26:b7:28:78:38:0f brd ff:ff:ff:ff:ff:ff altname eth0 Create a macro for walking the altnames, this hopefully makes it clearer that the list we walk contains only altnames. Which is otherwise not entirely intuitive. Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames") Signed-off-by: Jakub Kicinski --- CC: gnault@redhat.com CC: liuhangbin@gmail.com CC: lucien.xin@gmail.com CC: jiri@resnulli.us --- net/core/dev.c | 9 ++++++++- net/core/dev.h | 3 +++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index b08031957ffe..f4fa2692cf6d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1086,7 +1086,8 @@ static int __dev_alloc_name(struct net *net, const char *name, char *buf) for_each_netdev(net, d) { struct netdev_name_node *name_node; - list_for_each_entry(name_node, &d->name_node->list, list) { + + netdev_for_each_altname(d, name_node) { if (!sscanf(name_node->name, name, &i)) continue; if (i < 0 || i >= max_netdevices) @@ -11047,6 +11048,7 @@ EXPORT_SYMBOL(unregister_netdev); int __dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat, int new_ifindex) { + struct netdev_name_node *name_node; struct net *net_old = dev_net(dev); char new_name[IFNAMSIZ] = {}; int err, new_nsid; @@ -11079,6 +11081,11 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, if (err < 0) goto out; } + /* Check that none of the altnames conflicts. */ + err = -EEXIST; + netdev_for_each_altname(dev, name_node) + if (netdev_name_in_use(net, name_node->name)) + goto out; /* Check that new_ifindex isn't used yet. */ if (new_ifindex) { diff --git a/net/core/dev.h b/net/core/dev.h index e075e198092c..d093be175bd0 100644 --- a/net/core/dev.h +++ b/net/core/dev.h @@ -62,6 +62,9 @@ struct netdev_name_node { int netdev_get_name(struct net *net, char *name, int ifindex); int dev_change_name(struct net_device *dev, const char *newname); +#define netdev_for_each_altname(dev, name_node) \ + list_for_each_entry((name_node), &(dev)->name_node->list, list) + int netdev_name_node_alt_create(struct net_device *dev, const char *name); int netdev_name_node_alt_destroy(struct net_device *dev, const char *name); -- 2.41.0