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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 DDCD8C433ED for ; Sun, 4 Apr 2021 20:17:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E71261383 for ; Sun, 4 Apr 2021 20:17:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231407AbhDDURc (ORCPT ); Sun, 4 Apr 2021 16:17:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231327AbhDDURc (ORCPT ); Sun, 4 Apr 2021 16:17:32 -0400 Received: from zeniv-ca.linux.org.uk (zeniv-ca.linux.org.uk [IPv6:2607:5300:60:148a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35D06C0613E6; Sun, 4 Apr 2021 13:17:27 -0700 (PDT) Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94 #2 (Red Hat Linux)) id 1lT9BR-002XUa-Ug; Sun, 04 Apr 2021 20:17:22 +0000 Date: Sun, 4 Apr 2021 20:17:21 +0000 From: Al Viro To: Christian Brauner Cc: Jens Axboe , syzbot , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, io-uring@vger.kernel.org Subject: Re: [syzbot] WARNING in mntput_no_expire (2) Message-ID: References: <20210401174613.vymhhrfsemypougv@wittgenstein> <20210401175919.jpiylhfrlb4xb67u@wittgenstein> <20210404113445.xo6ntgfpxigcb3x6@wittgenstein> <20210404164040.vtxdcfzgliuzghwk@wittgenstein> <20210404170513.mfl5liccdaxjnpls@wittgenstein> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Sun, Apr 04, 2021 at 06:50:10PM +0000, Al Viro wrote: > > Yeah, I have at least namei.o > > > > https://drive.google.com/file/d/1AvO1St0YltIrA86DXjp1Xg3ojtS9owGh/view?usp=sharing > > *grumble* > > Is it reproducible without KASAN? Would be much easier to follow the produced > asm... Looks like inode_permission(_, NULL, _) from may_lookup(nd). I.e. nd->inode == NULL. Mind slapping BUG_ON(!nd->inode) right before may_lookup() call in link_path_walk() and trying to reproduce that oops?