From patchwork Sat Mar 8 04:47:26 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 14007417 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AC48514F9F9; Sat, 8 Mar 2025 04:47:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.177 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741409251; cv=none; b=PeALiap0DPb56qUUx1N8k0EXYm1b50OhUyTnO8QJ+sdD5dp/6ON5lvbbpIK7eg5mLqQCS2GUOWzzM+BSL0hvsiNkWVS+i2THKmd4LVxg1FjzyLUKBnfIzWnYU7WKmM3JMkBm/fXVandYTfjbwiru0yB6M1yyhJCCGaeaxXDnrZk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741409251; c=relaxed/simple; bh=3D+jBVMDzdXxgRO9ALyXgoL5Ci0t9RS4IUEZ1fzWwNc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=hMQevH8cQ1jvpfoHyMhkhj0i9FSwrNXqyQdzAoY8+3DPHsPyevSFDUdeID5t0vSdhPGxMnsP3CME/RqF83kBaWBE2W8N/1jdKyCJrJoTryYgT5Qn4CblIlqlFwA/MYISuHlxuczzdvZJII6y3lQlawL4bHjIusvlq2jPi4rQ5Vw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.214.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-223f4c06e9fso46002235ad.1; Fri, 07 Mar 2025 20:47:29 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741409248; x=1742014048; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=4U+v02y8A/g8OHY3lp2PwT5cFAoICJB3r4pAyC2rR4s=; b=uhiCZ/InrCkc+Z/5Ls4rh2BOcZ1ihDCbRKJY6xuC6eGQzrcXgzFjyYjqD+LXhGt2gj wC3iAJDVXqBC4cl0eKN3GwGR/25EVdNz1hYDZdkqkscQ9DdTQoC9t1jQcJu90qe699Er vKcJnL3oDaFaUpFwxpK+LU4ke5OfhpWpJkYUkY4q5FenfQ0VQhEvDzmSGLPwB5NbFzRz oZVlETn8KSzEmj6Cp+ymQHCt51AZR6K+ODaMeXM+edUXLsuyEptaiAswf442b/bJ4itZ 89G7H2pdhlfoz9vJdwRDq/R0nuy3vsRhX9Es7S75hjWrWiLCaSmkuJljWQRfm0h0KlFC Ce4Q== X-Forwarded-Encrypted: i=1; AJvYcCUl5s6bnSbk/6wpNlt9Jf8fbq8zL8Xz4TsPuE5N40wFVWqjmLRz3ziHYUbuiJ1CBOjP9ZT2EqNGy1YTfMjy@vger.kernel.org, AJvYcCVR6cXNCdvOuFzCcdhM24dm5pbVHrXVRJHF20PTu7iGInTo14ZT7s+akx2VFDW0i6rVbwUkJZrPIexDdV0mqHYz@vger.kernel.org, AJvYcCXiiE8w+IazvXetXH/Re8FN0rpLgrkuehZL4HeNGJHO96m3euYJfiynKM+Te7fbxX5rqCoy6pog6dE=@vger.kernel.org X-Gm-Message-State: AOJu0Ywle7cpDYXV8MIBFxz72asJs5jprCgdu85tOpUIBqTVhjOCeb9B oQ/b+kFIEBXX4jel6xCyOo5IyTjE0osRoUAi8iWJbrtc0tsuPIk1uFpz X-Gm-Gg: ASbGncv/Pbqun8vuXDLgI/vtweVX3F8HFEhTJ2oopikWuW4p253mUo+l0cBysNM5wz2 KDduJQiowKqLgp+kHnAqtAuy8Ycahbj1+Mr7ATi2AxBU2TX8MK60jmRrj/4vQW6i4rY6CmOd4bA sMSMSbjjdhXOnglAnbSR+Y4cgc0dyanf9dJljGAbarnvwycQUgrSS6gQAOGC0HHtQe4uTWrbl9j KAZoqiZT+2/TxzDUmeZhEqeEkG21XvD16j9gjmHQ7plRoXXFjgjqr0Scn5r2D89foiZBYUj7ps/ eFhdWl4UqxvM4OyqE9Fympr0Y2JdLDWA/0PUppb9owLV X-Google-Smtp-Source: AGHT+IFvsy6lprMK571V0NeoIWSZXlEdfTZEorJ3/9ymxQYI8szWuk8UX/tC3Jhz288kniaU0D0D5g== X-Received: by 2002:a17:902:e5c4:b0:223:607c:1d99 with SMTP id d9443c01a7336-2244b098559mr41725445ad.0.1741409248256; Fri, 07 Mar 2025 20:47:28 -0800 (PST) Received: from localhost ([2601:646:9e00:f56e:2844:3d8f:bf3e:12cc]) by smtp.gmail.com with UTF8SMTPSA id d9443c01a7336-22410ab8babsm38817355ad.251.2025.03.07.20.47.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Mar 2025 20:47:27 -0800 (PST) From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, horms@kernel.org, corbet@lwn.net, andrew+netdev@lunn.ch, pablo@netfilter.org, kadlec@netfilter.org, sdf@fomichev.me Subject: [PATCH net-next] net: revert to lockless TC_SETUP_BLOCK and TC_SETUP_FT Date: Fri, 7 Mar 2025 20:47:26 -0800 Message-ID: <20250308044726.1193222-1-sdf@fomichev.me> X-Mailer: git-send-email 2.48.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org There is a couple of places from which we can arrive to ndo_setup_tc with TC_SETUP_BLOCK/TC_SETUP_FT: - netlink - netlink notifier - netdev notifier Locking netdev too deep in this call chain seems to be problematic (especially assuming some/all of the call_netdevice_notifiers NETDEV_UNREGISTER) might soon be running with the instance lock). Revert to lockless ndo_setup_tc for TC_SETUP_BLOCK/TC_SETUP_FT. NFT framework already takes care of most of the locking. Document the assumptions. ndo_setup_tc TC_SETUP_BLOCK nft_block_offload_cmd nft_chain_offload_cmd nft_flow_block_chain nft_flow_offload_chain nft_flow_rule_offload_abort nft_flow_rule_offload_commit nft_flow_rule_offload_commit nf_tables_commit nfnetlink_rcv_batch nfnetlink_rcv_skb_batch nfnetlink_rcv nft_offload_netdev_event NETDEV_UNREGISTER notifier ndo_setup_tc TC_SETUP_FT nf_flow_table_offload_cmd nf_flow_table_offload_setup nft_unregister_flowtable_hook nft_register_flowtable_net_hooks nft_flowtable_update nf_tables_newflowtable nfnetlink_rcv_batch (.call NFNL_CB_BATCH) nft_flowtable_update nf_tables_newflowtable nft_flowtable_event nf_tables_flowtable_event NETDEV_UNREGISTER notifier __nft_unregister_flowtable_net_hooks nft_unregister_flowtable_net_hooks nf_tables_commit nfnetlink_rcv_batch (.call NFNL_CB_BATCH) __nf_tables_abort nf_tables_abort nfnetlink_rcv_batch __nft_release_hook __nft_release_hooks nf_tables_pre_exit_net -> module unload nft_rcv_nl_event netlink_register_notifier (oh boy) nft_register_flowtable_net_hooks nft_flowtable_update nf_tables_newflowtable nf_tables_newflowtable Fixes: c4f0f30b424e ("net: hold netdev instance lock during nft ndo_setup_tc") Signed-off-by: Stanislav Fomichev Reported-by: syzbot+0afb4bcf91e5a1afdcad@syzkaller.appspotmail.com Reviewed-by: Simon Horman --- Documentation/networking/netdevices.rst | 6 ++++++ include/linux/netdevice.h | 2 -- net/core/dev.c | 19 ------------------- net/netfilter/nf_flow_table_offload.c | 2 +- net/netfilter/nf_tables_offload.c | 2 +- 5 files changed, 8 insertions(+), 23 deletions(-) diff --git a/Documentation/networking/netdevices.rst b/Documentation/networking/netdevices.rst index d235a7364893..ebb868f50ac2 100644 --- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst @@ -290,6 +290,12 @@ struct net_device synchronization rules Synchronization: netif_addr_lock spinlock. Context: BHs disabled +ndo_setup_tc: + ``TC_SETUP_BLOCK`` and ``TC_SETUP_FT`` are running under NFT locks + (i.e. no ``rtnl_lock`` and no device instance lock). The rest of + ``tc_setup_type`` types run under netdev instance lock if the driver + implements queue management or shaper API. + Most ndo callbacks not specified in the list above are running under ``rtnl_lock``. In addition, netdev instance lock is taken as well if the driver implements queue management or shaper API. diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d206c9592b60..87fd3b1f2b99 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3395,8 +3395,6 @@ int dev_open(struct net_device *dev, struct netlink_ext_ack *extack); void netif_close(struct net_device *dev); void dev_close(struct net_device *dev); void dev_close_many(struct list_head *head, bool unlink); -int dev_setup_tc(struct net_device *dev, enum tc_setup_type type, - void *type_data); void netif_disable_lro(struct net_device *dev); void dev_disable_lro(struct net_device *dev); int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *newskb); diff --git a/net/core/dev.c b/net/core/dev.c index a0f75a1d1f5a..8b3603b764a7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1760,25 +1760,6 @@ void netif_close(struct net_device *dev) } } -int dev_setup_tc(struct net_device *dev, enum tc_setup_type type, - void *type_data) -{ - const struct net_device_ops *ops = dev->netdev_ops; - int ret; - - ASSERT_RTNL(); - - if (!ops->ndo_setup_tc) - return -EOPNOTSUPP; - - netdev_lock_ops(dev); - ret = ops->ndo_setup_tc(dev, type, type_data); - netdev_unlock_ops(dev); - - return ret; -} -EXPORT_SYMBOL(dev_setup_tc); - void netif_disable_lro(struct net_device *dev) { struct net_device *lower_dev; diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c index 0ec4abded10d..e06bc36f49fe 100644 --- a/net/netfilter/nf_flow_table_offload.c +++ b/net/netfilter/nf_flow_table_offload.c @@ -1175,7 +1175,7 @@ static int nf_flow_table_offload_cmd(struct flow_block_offload *bo, nf_flow_table_block_offload_init(bo, dev_net(dev), cmd, flowtable, extack); down_write(&flowtable->flow_block_lock); - err = dev_setup_tc(dev, TC_SETUP_FT, bo); + err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_FT, bo); up_write(&flowtable->flow_block_lock); if (err < 0) return err; diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c index b761899c143c..64675f1c7f29 100644 --- a/net/netfilter/nf_tables_offload.c +++ b/net/netfilter/nf_tables_offload.c @@ -390,7 +390,7 @@ static int nft_block_offload_cmd(struct nft_base_chain *chain, nft_flow_block_offload_init(&bo, dev_net(dev), cmd, chain, &extack); - err = dev_setup_tc(dev, TC_SETUP_BLOCK, &bo); + err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo); if (err < 0) return err;