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GET /api/patches/2231614/?format=api
{ "id": 2231614, "url": "http://patchwork.ozlabs.org/api/patches/2231614/?format=api", "web_url": "http://patchwork.ozlabs.org/project/openvswitch/patch/20260430233848.440994-2-i.maximets@ovn.org/", "project": { "id": 47, "url": "http://patchwork.ozlabs.org/api/projects/47/?format=api", "name": "Open vSwitch", "link_name": "openvswitch", "list_id": "ovs-dev.openvswitch.org", "list_email": "ovs-dev@openvswitch.org", "web_url": "http://openvswitch.org/", "scm_url": "git@github.com:openvswitch/ovs.git", "webscm_url": "https://github.com/openvswitch/ovs", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260430233848.440994-2-i.maximets@ovn.org>", "list_archive_url": null, "date": "2026-04-30T23:38:37", "name": "[ovs-dev,net,v2,1/2] openvswitch: vport: fix self-deadlock on release of tunnel ports", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "57dfc576a267b0224ba92f1c523a39cbc024d30a", "submitter": { "id": 76798, "url": "http://patchwork.ozlabs.org/api/people/76798/?format=api", "name": "Ilya Maximets", "email": "i.maximets@ovn.org" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/openvswitch/patch/20260430233848.440994-2-i.maximets@ovn.org/mbox/", "series": [ { "id": 502405, "url": "http://patchwork.ozlabs.org/api/series/502405/?format=api", "web_url": "http://patchwork.ozlabs.org/project/openvswitch/list/?series=502405", "date": "2026-04-30T23:38:37", "name": "openvswitch: fix self-deadlock on release of tunnel vports", "version": 2, "mbox": "http://patchwork.ozlabs.org/series/502405/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2231614/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2231614/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<ovs-dev-bounces@openvswitch.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "dev@openvswitch.org" ], "Delivered-To": [ "patchwork-incoming@legolas.ozlabs.org", "ovs-dev@lists.linuxfoundation.org" ], "Authentication-Results": [ "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=openvswitch.org\n (client-ip=2605:bc80:3010::137; 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Thu, 30 Apr 2026 23:39:07 +0000 (UTC)", "from localhost (localhost [127.0.0.1])\n by smtp4.osuosl.org (Postfix) with ESMTP id 04EA142155\n for <dev@openvswitch.org>; Thu, 30 Apr 2026 23:39:07 +0000 (UTC)", "from smtp4.osuosl.org ([127.0.0.1])\n by localhost (smtp4.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP\n id VM5993wgx6-W for <dev@openvswitch.org>;\n Thu, 30 Apr 2026 23:39:06 +0000 (UTC)", "from mail-qt1-f196.google.com (mail-qt1-f196.google.com\n [209.85.160.196])\n by smtp4.osuosl.org (Postfix) with ESMTPS id 452C24214F\n for <dev@openvswitch.org>; Thu, 30 Apr 2026 23:39:06 +0000 (UTC)", "by mail-qt1-f196.google.com with SMTP id\n d75a77b69052e-50fb8e9a4edso16376441cf.1\n for <dev@openvswitch.org>; Thu, 30 Apr 2026 16:39:06 -0700 (PDT)", "from im-t490s.redhat.com (89-24-32-159.nat.epc.tmcz.cz.\n [89.24.32.159]) by smtp.gmail.com with ESMTPSA id\n d75a77b69052e-51040934199sm221cf.13.2026.04.30.16.39.02\n (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n Thu, 30 Apr 2026 16:39:04 -0700 (PDT)" ], "X-Virus-Scanned": [ "amavis at osuosl.org", "amavis at osuosl.org" ], "X-Comment": "SPF check N/A for local connections - client-ip=140.211.9.56;\n helo=lists.linuxfoundation.org;\n envelope-from=ovs-dev-bounces@openvswitch.org; receiver=<UNKNOWN> ", "DKIM-Filter": [ "OpenDKIM Filter v2.11.0 smtp4.osuosl.org 73D184216B", "OpenDKIM Filter v2.11.0 smtp4.osuosl.org 452C24214F" ], "Received-SPF": "Pass (mailfrom) identity=mailfrom; client-ip=209.85.160.196;\n helo=mail-qt1-f196.google.com; envelope-from=i.maximets.ovn@gmail.com;\n receiver=<UNKNOWN>", "DMARC-Filter": "OpenDMARC Filter v1.4.2 smtp4.osuosl.org 452C24214F", "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=1e100.net; s=20251104; t=1777592345; x=1778197145;\n h=content-transfer-encoding:mime-version:references:in-reply-to\n :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from\n :to:cc:subject:date:message-id:reply-to;\n bh=SA+eWHMkILjGV4lZwdF0bh9/zh8ox7+jWKzlWflnjB8=;\n b=PLG5aBlXHcWhW23cS8/nE3fyDsHOeDWLi6r4nQ2oXGmY4TryRUSOo0O/ADqKIprZS0\n yCm5qboFvlzLMoLkhgrmveNGcHZa+kvj5wW18mg3GtNeq3nVm+vSQBO8gm8Hu95iUA9o\n 4I35qblxcu723PCanWWhrROdpQI0a2xQyUwtZM73o1FJPJXEdJk0Cr9TdnHonujtViyb\n eEHZjyyjjUBkPSe//ud0ZdpSLzeWaytXqrCq9Fk4ywgYHraddEGMB4SgXkfo8cYOCIFY\n +5zQ0QqOxIFYpYP1uXyFswtZWyMXdfseHep10/AWDe/ZShao/YV4WzhcEIPG7R1b3Ank\n bCYg==", "X-Forwarded-Encrypted": "i=1;\n AFNElJ+r6S0xpiZ9dPJ0YcDMU7P/SvrqnDwc78S43a43iOCWm34j8NZNN3tyRhwBzmSiQeIrq9Y=@openvswitch.org", "X-Gm-Message-State": "AOJu0Yxr5Ho0Ol22DrfsE17NcnB+yAELj7EG1ENQ82o5cpjMhIbl7p+w\n W96wNcp+07xylb3/1xu6gcj8qa8lQXytX82Ukyb9+x7fBZtbu3VUohwR", "X-Gm-Gg": "AeBDiesPfi7ua/5MdJxyHwVP97Hfzaj+gcmUR9Y4wu/2kzP3kicGYX/pZY24mXsqYOG\n K9Xq3kCt8lfUNiXPgqspLYhDiLhJrghi7IELCDvXoi4EQpn/XUiXOYgbPGvOau3N7wVJmn2bdQG\n BsPCGljIyLp3xHADuVrWaPKhPbKg8XM6m3IdK+A+wY5cRP77gfey6DNRsu/Ave7QteHQt3HJu5p\n 66FAS8XwsQo+YLtLlUm4Ncl39D7oOC80ffH3iCn/VVBii7jfa5wKae+VrbeBW09ZGmriDsU61yI\n 23Ou0bHj8d1N0N0uSW64b/Q2VQqdVVPiO4iFW/tORWn/hYXr5HzO0QwfphK65pKLVLZqIaWk99v\n weCoAbfbz1VtzJt4NM16rB4jtjXmhdOJ9vEIJhfxdITgPzvFOlYPJtlUUe7MXWlZBiZkZrdKVqU\n 4q3Aosz8HAt2sQWplZkVLQeWOGsccykQOgqxV+s+jB8DSwYkaxcxxcaPljkDBG1vM7/iA0aQ==", "X-Received": "by 2002:ac8:5a0e:0:b0:50d:8db0:7abb with SMTP id\n d75a77b69052e-5102adc9563mr74431601cf.42.1777592344891;\n Thu, 30 Apr 2026 16:39:04 -0700 (PDT)", "From": "Ilya Maximets <i.maximets@ovn.org>", "To": "netdev@vger.kernel.org", "Date": "Fri, 1 May 2026 01:38:37 +0200", "Message-ID": "<20260430233848.440994-2-i.maximets@ovn.org>", "X-Mailer": "git-send-email 2.53.0", "In-Reply-To": "<20260430233848.440994-1-i.maximets@ovn.org>", "References": "<20260430233848.440994-1-i.maximets@ovn.org>", "MIME-Version": "1.0", "Subject": "[ovs-dev] [PATCH net v2 1/2] openvswitch: vport: fix self-deadlock\n on release of tunnel ports", "X-BeenThere": "ovs-dev@openvswitch.org", "X-Mailman-Version": "2.1.30", "Precedence": "list", "List-Id": "<ovs-dev.openvswitch.org>", "List-Unsubscribe": "<https://mail.openvswitch.org/mailman/options/ovs-dev>,\n <mailto:ovs-dev-request@openvswitch.org?subject=unsubscribe>", "List-Archive": "<http://mail.openvswitch.org/pipermail/ovs-dev/>", "List-Post": "<mailto:ovs-dev@openvswitch.org>", "List-Help": "<mailto:ovs-dev-request@openvswitch.org?subject=help>", "List-Subscribe": "<https://mail.openvswitch.org/mailman/listinfo/ovs-dev>,\n <mailto:ovs-dev-request@openvswitch.org?subject=subscribe>", "Cc": "dev@openvswitch.org, linux-kselftest@vger.kernel.org,\n Yuan Tan <tanyuan98@outlook.com>, linux-kernel@vger.kernel.org,\n Ilya Maximets <i.maximets@ovn.org>, Yang Yang <n05ec@lzu.edu.cn>,\n Eric Dumazet <edumazet@google.com>, stable@vger.kernel.org,\n Simon Horman <horms@kernel.org>, Jakub Kicinski <kuba@kernel.org>,\n Paolo Abeni <pabeni@redhat.com>, Shuah Khan <shuah@kernel.org>,\n \"David S. Miller\" <davem@davemloft.net>", "Content-Type": "text/plain; charset=\"us-ascii\"", "Content-Transfer-Encoding": "7bit", "Errors-To": "ovs-dev-bounces@openvswitch.org", "Sender": "\"dev\" <ovs-dev-bounces@openvswitch.org>" }, "content": "vports are used concurrently and protected by RCU, so netdev_put()\nmust happen after the RCU grace period. So, either in an RCU call or\nafter the synchronize_net(). The rtnl_delete_link() must happen under\nRTNL and so can't be executed in RCU context. Calling synchronize_net()\nwhile holding RTNL is not a good idea for performance and system\nstability under load in general, so calling netdev_put() in RCU call\nis the right solution here.\n\nHowever,\nwhen the device is deleted, rtnl_unlock() will call netdev_run_todo()\nand block until all the references are gone. In the current code this\nmeans that we never reach the call_rcu() and the vport is never freed\nand the reference is never released, causing a self-deadlock on device\nremoval.\n\nFix that by moving the rcu_call() before the rtnl_unlock(), so the\nscheduled RCU callback will be executed when synchronize_net() is\ncalled from the rtnl_unlock()->netdev_run_todo() while the RTNL itself\nis already released.\n\nFixes: 6931d21f87bc (\"openvswitch: defer tunnel netdev_put to RCU release\")\nCc: stable@vger.kernel.org\nAcked-by: Eelco Chaudron <echaudro@redhat.com>\nSigned-off-by: Ilya Maximets <i.maximets@ovn.org>\n---\n net/openvswitch/vport-netdev.c | 6 +++++-\n 1 file changed, 5 insertions(+), 1 deletion(-)", "diff": "diff --git a/net/openvswitch/vport-netdev.c b/net/openvswitch/vport-netdev.c\nindex 12055af832dc0..a1df551e915bc 100644\n--- a/net/openvswitch/vport-netdev.c\n+++ b/net/openvswitch/vport-netdev.c\n@@ -196,9 +196,13 @@ void ovs_netdev_tunnel_destroy(struct vport *vport)\n \t */\n \tif (vport->dev->reg_state == NETREG_REGISTERED)\n \t\trtnl_delete_link(vport->dev, 0, NULL);\n-\trtnl_unlock();\n \n+\t/* We can't put the device reference yet, since it can still be in\n+\t * use, but rtnl_unlock()->netdev_run_todo() will block until all\n+\t * the references are released, so the RCU call must be before it.\n+\t */\n \tcall_rcu(&vport->rcu, vport_netdev_free);\n+\trtnl_unlock();\n }\n EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy);\n \n", "prefixes": [ "ovs-dev", "net", "v2", "1/2" ] }