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=-2.1 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 3C5D0C388F3 for ; Tue, 1 Oct 2019 08:45:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 130AD215EA for ; Tue, 1 Oct 2019 08:45:48 +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="QeGWiE1g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733144AbfJAIpr (ORCPT ); Tue, 1 Oct 2019 04:45:47 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:34144 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726148AbfJAIpq (ORCPT ); Tue, 1 Oct 2019 04:45:46 -0400 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=vAyI0/IqfKtg27NjkVN0J7lLOBnn0EBImm7wCc67a1Y=; b=QeGWiE1gSJRrkjtogdlwI+JRc y9HYd8MDarEx7hsx7JSh56yK+pJnydYyYWM8+eKo0IMemAsS/N9/1Z/cEERn2dRW/BLF5S+FAbKRP tFmSwGKJUhtt/+/U1FhrxbTu/7Q6IfsQph+mLRv2unWyfe6UgWK3XLECzJ8C4RqTVmMBWaKIl+TOh oPwp6AON6VUcvApnI/BqfEuCa4Ye42Am0OvEcoVJEK6puPxH5xRrsVLBUHghFDTrq5X3Sl11gFKS8 ZKUri4PPH4GNl9t4ugQzfOoeoL09ZvTQIwtBAQgGNmSlSedE/jAYYnJ270iQrT8l6PJaTl/iryLbt qqN2trgyg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.2 #3 (Red Hat Linux)) id 1iFDmw-0006lV-3y; Tue, 01 Oct 2019 08:45:42 +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 0D354305E4E; Tue, 1 Oct 2019 10:44:52 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 627FD265261AD; Tue, 1 Oct 2019 10:45:40 +0200 (CEST) Date: Tue, 1 Oct 2019 10:45:40 +0200 From: Peter Zijlstra To: syzbot Cc: bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Subject: Re: WARNING: lock held when returning to user space in membarrier_private_expedited Message-ID: <20191001084540.GO4519@hirez.programming.kicks-ass.net> References: <000000000000ceadfd0593d4dd55@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000ceadfd0593d4dd55@google.com> 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, Oct 01, 2019 at 01:09:07AM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: afb37288 Add linux-next specific files for 20191001 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=17619635600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=659cb5bf73e72c6c > dashboard link: https://syzkaller.appspot.com/bug?extid=6b6a46cc150b19f54ad6 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=176faa13600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14b825cd600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+6b6a46cc150b19f54ad6@syzkaller.appspotmail.com > > ================================================ > WARNING: lock held when returning to user space! > 5.4.0-rc1-next-20191001 #0 Not tainted > ------------------------------------------------ > syz-executor589/9088 is leaving the kernel with locks still held! > 1 lock held by syz-executor589/9088: > #0: ffffffff88faadc0 (rcu_read_lock){....}, at: > membarrier_private_expedited+0x180/0x590 kernel/sched/membarrier.c:150 https://lkml.kernel.org/r/20191001071921.GJ4519@hirez.programming.kicks-ass.net