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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 16A11C33C8C for ; Tue, 7 Jan 2020 13:12:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD8712072A for ; Tue, 7 Jan 2020 13:12:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y9TuhSxt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728160AbgAGNMC (ORCPT ); Tue, 7 Jan 2020 08:12:02 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:35738 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727834AbgAGNMB (ORCPT ); Tue, 7 Jan 2020 08:12:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=3roxz6guEJ/YxIFLVeBH//5xGM64ZcJTUKnaWntqOek=; b=Y9TuhSxtHADNgC+2XWQQAGths ovny7OuepH+xVuWPmyn4B+ua4SVqEtowwCDWlINRJv0VJ2VP0ymXprj00rnSN8JT5OVwQFETUW6qO BbpldV8TlVGvgWQlTA0oLWB51Oa07YC1RCBnL9uGQlvFSWiF60KfIFA8nlsHJ/q83J26Shk4eWW5M 0UOXVUP4U5BpVHf+OD346c8iMFtjIwtAOK3GoKe5xPnZ9KMLWhnuGzQ8Swi8DF+lkAlzF/wa+ej8n 0LPFr0wJS9UE0hwrkWNWNlKhqrbYPONIglqfj4iMRRpSFxcfYFIhDo6qHDOawg4JyrXqKDYk4lZFy QVjRRrheg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iooeC-0004hQ-Gg; Tue, 07 Jan 2020 13:11:48 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 817633012C3; Tue, 7 Jan 2020 14:10:13 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 19BEE20D3D423; Tue, 7 Jan 2020 14:11:46 +0100 (CET) Date: Tue, 7 Jan 2020 14:11:46 +0100 From: Peter Zijlstra To: Dmitry Vyukov Cc: Tetsuo Handa , syzbot , syzkaller-bugs , Ingo Molnar , James Morris , LKML , linux-security-module , "Serge E. Hallyn" , syzkaller Subject: Re: INFO: rcu detected stall in sys_sendfile64 Message-ID: <20200107131146.GX2827@hirez.programming.kicks-ass.net> References: <000000000000e728ec057d5c9d90@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 07, 2020 at 02:02:47PM +0100, Dmitry Vyukov wrote: > > >> This is not a LSM problem, for the reproducer is calling > > >> sched_setattr(SCHED_DEADLINE) with very large values. > > >> > > >> sched_setattr(0, {size=0, sched_policy=0x6 /* SCHED_??? */, sched_flags=0, sched_nice=0, sched_priority=0, sched_runtime=2251799813724439, sched_deadline=4611686018427453437, sched_period=0}, 0) = 0 > > >> > > >> I think that this problem is nothing but an insane sched_setattr() parameter. Argh, I had a patch for that somewhere. Let me go dig that out.