From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D373C001DC for ; Sat, 29 Jul 2023 15:28:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232036AbjG2P2o (ORCPT ); Sat, 29 Jul 2023 11:28:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231786AbjG2P2n (ORCPT ); Sat, 29 Jul 2023 11:28:43 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 792822D71 for ; Sat, 29 Jul 2023 08:27:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690644475; 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: in-reply-to:in-reply-to:references:references; bh=lYrjzDXQBP1JQED32eZ0I4QHdIQUaEv+ENeIzB1hNE4=; b=Oa0P0Ab8ngSHqGQMQitZjHoiWvdvmoAlxc1AQ0mCDjf0d1yTrMdny23Nl9uAcXzuwuDx3r vdNT7Tr1v80Z2xiAnxpJ5HQQOUMjD8h252+hR733o0/12NpRgko6lrbqLG03HsyjYEcYHJ arnf89JeMivpJiPZLJMpsx5DIL1KT1Q= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-133-HJQnEaRMPCORiA55xTOVMA-1; Sat, 29 Jul 2023 11:27:52 -0400 X-MC-Unique: HJQnEaRMPCORiA55xTOVMA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 34FDD3803507; Sat, 29 Jul 2023 15:27:50 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.131]) by smtp.corp.redhat.com (Postfix) with ESMTP id 91BE1140E949; Sat, 29 Jul 2023 15:27:48 +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 From: David Howells In-Reply-To: <550503.1690588340@warthog.procyon.org.uk> References: <550503.1690588340@warthog.procyon.org.uk> <20230718160737.52c68c73@kernel.org> <000000000000881d0606004541d1@google.com> <0000000000001416bb06004ebf53@google.com> To: Jakub Kicinski Cc: dhowells@redhat.com, syzbot , bpf@vger.kernel.org, brauner@kernel.org, davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Subject: Re: [syzbot] [fs?] INFO: task hung in pipe_release (4) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <713502.1690644467.1@warthog.procyon.org.uk> Date: Sat, 29 Jul 2023 16:27:47 +0100 Message-ID: <713503.1690644467@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org David Howells wrote: > I've managed to reproduce it finally. Instrumenting the pipe_lock/unlock > functions, splice_to_socket() and pipe_release() seems to show that > pipe_release() is being called whilst splice_to_socket() is still running. That's actually a bit of a red herring. pipe_release() is so-called because it's called as the release file op for an end of the pipe. It doesn't automatically free the pipe_inode_info struct - there's refcounting on that. So the problem is that udp_sendmsg() didn't return; pipe_release() hanging on the pipe_lock() is merely a noisy symptom thereof. David