From patchwork Fri Jan 29 23:53:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 373993 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75FB5C433E0 for ; Fri, 29 Jan 2021 23:55:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28C7064E00 for ; Fri, 29 Jan 2021 23:55:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232109AbhA2XzY (ORCPT ); Fri, 29 Jan 2021 18:55:24 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46853 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231199AbhA2XzW (ORCPT ); Fri, 29 Jan 2021 18:55:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611964435; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=q039E6qRHMWcEvS57m0H092hcBFMkfO15L+0InB6KMY=; b=a6BCdsudDJeI0hSzI/hdMhA2/W9kGU0SQUO97Vtg3BsxKJY6QqAc4zHZT+oH1oUT6QAuWb YbJ0GY/XBoUNmCEvEr9O+qjEmBL5Jnjp6y7Hn5B+9VhZaOGEEVDNoR+ro8PW76iJkAG7zJ 1MoH1a1OSUC0YP48gP/1Ny5QJii4Fhg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-353-wQPqnrndOFmV70fhnBJ3Yg-1; Fri, 29 Jan 2021 18:53:53 -0500 X-MC-Unique: wQPqnrndOFmV70fhnBJ3Yg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5BD4D10054FF; Fri, 29 Jan 2021 23:53:52 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-115-23.rdu2.redhat.com [10.10.115.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 34E735D71B; Fri, 29 Jan 2021 23:53:50 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH net] rxrpc: Fix deadlock around release of dst cached on udp tunnel From: David Howells To: netdev@vger.kernel.org Cc: syzbot+df400f2f24a1677cd7e0@syzkaller.appspotmail.com, Vadim Fedorenko , Vadim Fedorenko , vfedorenko@novek.ru, dhowells@redhat.com, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Date: Fri, 29 Jan 2021 23:53:50 +0000 Message-ID: <161196443016.3868642.5577440140646403533.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org AF_RXRPC sockets use UDP ports in encap mode. This causes socket and dst from an incoming packet to get stolen and attached to the UDP socket from whence it is leaked when that socket is closed. When a network namespace is removed, the wait for dst records to be cleaned up happens before the cleanup of the rxrpc and UDP socket, meaning that the wait never finishes. Fix this by moving the rxrpc (and, by dependence, the afs) private per-network namespace registrations to the device group rather than subsys group. This allows cached rxrpc local endpoints to be cleared and their UDP sockets closed before we try waiting for the dst records. The symptom is that lines looking like the following: unregister_netdevice: waiting for lo to become free get emitted at regular intervals after running something like the referenced syzbot test. Thanks to Vadim for tracking this down and work out the fix. Reported-by: syzbot+df400f2f24a1677cd7e0@syzkaller.appspotmail.com Reported-by: Vadim Fedorenko Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: David Howells Acked-by: Vadim Fedorenko --- fs/afs/main.c | 6 +++--- net/rxrpc/af_rxrpc.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/afs/main.c b/fs/afs/main.c index accdd8970e7c..b2975256dadb 100644 --- a/fs/afs/main.c +++ b/fs/afs/main.c @@ -193,7 +193,7 @@ static int __init afs_init(void) goto error_cache; #endif - ret = register_pernet_subsys(&afs_net_ops); + ret = register_pernet_device(&afs_net_ops); if (ret < 0) goto error_net; @@ -213,7 +213,7 @@ static int __init afs_init(void) error_proc: afs_fs_exit(); error_fs: - unregister_pernet_subsys(&afs_net_ops); + unregister_pernet_device(&afs_net_ops); error_net: #ifdef CONFIG_AFS_FSCACHE fscache_unregister_netfs(&afs_cache_netfs); @@ -244,7 +244,7 @@ static void __exit afs_exit(void) proc_remove(afs_proc_symlink); afs_fs_exit(); - unregister_pernet_subsys(&afs_net_ops); + unregister_pernet_device(&afs_net_ops); #ifdef CONFIG_AFS_FSCACHE fscache_unregister_netfs(&afs_cache_netfs); #endif diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 0a2f4817ec6c..41671af6b33f 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -990,7 +990,7 @@ static int __init af_rxrpc_init(void) goto error_security; } - ret = register_pernet_subsys(&rxrpc_net_ops); + ret = register_pernet_device(&rxrpc_net_ops); if (ret) goto error_pernet; @@ -1035,7 +1035,7 @@ static int __init af_rxrpc_init(void) error_sock: proto_unregister(&rxrpc_proto); error_proto: - unregister_pernet_subsys(&rxrpc_net_ops); + unregister_pernet_device(&rxrpc_net_ops); error_pernet: rxrpc_exit_security(); error_security: @@ -1057,7 +1057,7 @@ static void __exit af_rxrpc_exit(void) unregister_key_type(&key_type_rxrpc); sock_unregister(PF_RXRPC); proto_unregister(&rxrpc_proto); - unregister_pernet_subsys(&rxrpc_net_ops); + unregister_pernet_device(&rxrpc_net_ops); ASSERTCMP(atomic_read(&rxrpc_n_tx_skbs), ==, 0); ASSERTCMP(atomic_read(&rxrpc_n_rx_skbs), ==, 0);