From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 645C21DDE5 for ; Tue, 11 Jul 2023 23:54:30 +0000 (UTC) Received: from smtp-fw-9106.amazon.com (smtp-fw-9106.amazon.com [207.171.188.206]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E567F170F for ; Tue, 11 Jul 2023 16:54:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1689119669; x=1720655669; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=S31tc4n4Ui6HS+LailK8v4AO1tjvB2dHTdcwzIgGBFk=; b=fsaCeF2b7BODBn9dkEYnt0kziFvuHCDiVjV0clIAnMGJmsoxSjCMBoH8 CSwkfkWb2GXz3kL4abrqFs0BugDi6bBGUWWsWBQdMvBLFKaSGUgncdw9M R2MIxvdnJPoXLu7AGRJynRyg/X07EqAkndj3I9Bydy4csWnkC1vZ9c2CA M=; X-IronPort-AV: E=Sophos;i="6.01,198,1684800000"; d="scan'208";a="659347303" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-pdx-2a-m6i4x-af372327.us-west-2.amazon.com) ([10.25.36.214]) by smtp-border-fw-9106.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2023 23:54:28 +0000 Received: from EX19MTAUWC001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan3.pdx.amazon.com [10.236.137.198]) by email-inbound-relay-pdx-2a-m6i4x-af372327.us-west-2.amazon.com (Postfix) with ESMTPS id D1D4C60CBB; Tue, 11 Jul 2023 23:54:27 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWC001.ant.amazon.com (10.250.64.174) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.30; Tue, 11 Jul 2023 23:54:27 +0000 Received: from 88665a182662.ant.amazon.com (10.187.170.35) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.30; Tue, 11 Jul 2023 23:54:24 +0000 From: Kuniyuki Iwashima To: Roopa Prabhu , Nikolay Aleksandrov , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: "Eric W. Biederman" , Kuniyuki Iwashima , Kuniyuki Iwashima , , , Harry Coin Subject: [PATCH v1 net] bridge: Return an error when enabling STP in netns. Date: Tue, 11 Jul 2023 16:54:15 -0700 Message-ID: <20230711235415.92166-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.187.170.35] X-ClientProxiedBy: EX19D041UWA002.ant.amazon.com (10.13.139.121) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: Bulk X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,T_SCC_BODY_TEXT_LINE,T_SPF_PERMERROR autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net When we create an L2 loop on a bridge in netns, we will see packets storm even if STP is enabled. # unshare -n # ip link add br0 type bridge # ip link add veth0 type veth peer name veth1 # ip link set veth0 master br0 up # ip link set veth1 master br0 up # ip link set br0 type bridge stp_state 1 # ip link set br0 up # sleep 30 # ip -s link show br0 2: br0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether b6:61:98:1c:1c:b5 brd ff:ff:ff:ff:ff:ff RX: bytes packets errors dropped missed mcast 956553768 12861249 0 0 0 12861249 <-. Keep TX: bytes packets errors dropped carrier collsns | increasing 1027834 11951 0 0 0 0 <-' rapidly This is because llc_rcv() drops all packets in non-root netns and BPDU is dropped. Let's show an error when enabling STP in netns. # unshare -n # ip link add br0 type bridge # ip link set br0 type bridge stp_state 1 Error: bridge: STP can't be enabled in non-root netns. Note this commit will be reverted later when we namespacify the whole LLC infra. Fixes: e730c15519d0 ("[NET]: Make packet reception network namespace safe") Suggested-by: Harry Coin Link: https://lore.kernel.org/netdev/0f531295-e289-022d-5add-5ceffa0df9bc@quietfountain.com/ Signed-off-by: Kuniyuki Iwashima --- net/bridge/br_stp_if.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index 75204d36d7f9..a807996ac56b 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -201,6 +201,11 @@ int br_stp_set_enabled(struct net_bridge *br, unsigned long val, { ASSERT_RTNL(); + if (!net_eq(dev_net(br->dev), &init_net)) { + NL_SET_ERR_MSG_MOD(extack, "STP can't be enabled in non-root netns"); + return -EINVAL; + } + if (br_mrp_enabled(br)) { NL_SET_ERR_MSG_MOD(extack, "STP can't be enabled if MRP is already enabled"); -- 2.30.2