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 CA237C001B0 for ; Mon, 24 Jul 2023 13:18:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230263AbjGXNSF (ORCPT ); Mon, 24 Jul 2023 09:18:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230172AbjGXNSC (ORCPT ); Mon, 24 Jul 2023 09:18:02 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1174DA for ; Mon, 24 Jul 2023 06:17:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690204635; 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: in-reply-to:in-reply-to:references:references; bh=f4KQ/tLol2JTMF9SoFlYCSkzvClZr/k6u6hh/oPakP4=; b=C54Uy60caZtkkJNESvMeQ4Oi/x5XIQFMoa/5mIansrjwsdAWGalnTEBi7ktHCCsrx0gO/f sgWE4WbwwSSeihXYo7kFj52/F/7URoAJStq+6M6m2CB3qP2kY/PHUQq0jjwmOvzHe1rhNf xPjZCuyk5D9ILysWkeNqaS6X2FUGfbo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-526-F2Wq1qF6PVuCC9PMRtj6hg-1; Mon, 24 Jul 2023 09:17:11 -0400 X-MC-Unique: F2Wq1qF6PVuCC9PMRtj6hg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 73D201010427; Mon, 24 Jul 2023 13:17:10 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.116]) by smtp.corp.redhat.com (Postfix) with ESMTP id D8ECA200BA63; Mon, 24 Jul 2023 13:17:08 +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: <0000000000001416bb06004ebf53@google.com> References: <0000000000001416bb06004ebf53@google.com> To: syzbot Cc: dhowells@redhat.com, bpf@vger.kernel.org, brauner@kernel.org, davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, kuba@kernel.org, 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: <145369.1690204627.1@warthog.procyon.org.uk> Content-Transfer-Encoding: quoted-printable Date: Mon, 24 Jul 2023 14:17:07 +0100 Message-ID: <145370.1690204627@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Note that the test program is dodgy: pipe(&(0x7f0000000100)=3D{0xffffffffffffffff, 0xffffffff= ffffffff}) r2 =3D socket$inet_udp(0x2, 0x2, 0x0) r2 is closed here: close(r2) r3 =3D socket$inet_udp(0x2, 0x2, 0x0) setsockopt$sock_int(r3, 0x1, 0x6, &(0x7f0000000140)=3D0x32, 0x4) bind$inet(r3, &(0x7f0000000000)=3D{0x2, 0x0, @dev=3D{0xac, 0x14, 0x14,= 0x15}}, 0x10) connect$inet(r3, &(0x7f0000000200)=3D{0x2, 0x0, @broadcast}, 0x10) sendmmsg(r3, &(0x7f0000000180)=3D[{{0x0, 0x0, 0x0}}, {{0x0, 0xffffffff= fffffed3, &(0x7f0000000940)=3D[{&(0x7f00000006c0)=3D'O', 0x57e}], 0x1}}], = 0x4000000000003bd, 0x8800) write$binfmt_misc(r1, &(0x7f0000000440)=3DANY=3D[], 0x8) but then used here: splice(r0, 0x0, r2, 0x0, 0x4ffe0, 0x0) As it happens, r3 will probably end up referring to the same fd as r2 did,= but that's not guaranteed. David