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 B70AB1ED38 for ; Tue, 25 Jul 2023 11:32:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3AC93C433C8; Tue, 25 Jul 2023 11:32:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690284774; bh=JDdpaKhAeiv9MkKxvAlB2lK1hp533pI//KKAPqtaJwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cpfNElS7nvazeR0yR4qqLPidnloakBcVzH4wx/++QCc7EVaTZ4fNDFv4qMGQ4NH7d Us15DH1BAd7xu9lPnCyxglc0JlYUr+kJg3IhATCOaJ5LuBDKN4UBYrv7OeuTS1+edI 5QSfaq21J8HcMVBzaSZEl3tJbwEbcbTb8J9aWI04= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Harry Coin , Ido Schimmel , Kuniyuki Iwashima , Nikolay Aleksandrov , Ido Schimmel , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 477/509] bridge: Add extack warning when enabling STP in netns. Date: Tue, 25 Jul 2023 12:46:56 +0200 Message-ID: <20230725104615.592659139@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104553.588743331@linuxfoundation.org> References: <20230725104553.588743331@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Kuniyuki Iwashima [ Upstream commit 56a16035bb6effb37177867cea94c13a8382f745 ] 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 add extack warning when enabling STP in netns. # unshare -n # ip link add br0 type bridge # ip link set br0 type bridge stp_state 1 Warning: bridge: STP does not work 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/ Suggested-by: Ido Schimmel Signed-off-by: Kuniyuki Iwashima Acked-by: Nikolay Aleksandrov Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/bridge/br_stp_if.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index ba55851fe132c..3326dfced68ab 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -201,6 +201,9 @@ 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 does not work in non-root netns"); + if (br_mrp_enabled(br)) { NL_SET_ERR_MSG_MOD(extack, "STP can't be enabled if MRP is already enabled"); -- 2.39.2