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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 1A4E2C2BA2B for ; Sat, 11 Apr 2020 16:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E83EE2084D for ; Sat, 11 Apr 2020 16:14:46 +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="E0NjrzbC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726204AbgDKQOm (ORCPT ); Sat, 11 Apr 2020 12:14:42 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:41618 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726069AbgDKQOm (ORCPT ); Sat, 11 Apr 2020 12:14:42 -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; bh=4kLMPck/UQTFbc7P/dtGX9z+C5HE2yHjGcXQaPeD8UE=; b=E0NjrzbCb12cq87rjgyqkwADEW WAHh8mUUwTfsCROLuFG0kbje7DyHccwxOL380SlXlKeGnNjF1bsciAybqAPEmO8A+J3X/1QtH19Xy +53Ux1fcD5TfDsE20RWsl8RObPX1qW5c/K8rzmTk33ONfOLvRz5d9IxM2p2Mk2goeNMYjwze1O3GY wsHu/ins6D7MCHyncSooKHUIilEp5z9YHm1zyBXzOE1V+Lb9jhS0nG2IcuDAzTWSwUQccjqgQR0Qa hm8ooSvlQZJLMhV/HFq1p6r1rlkDX3/SDeHLpj5W2lvCoWJKUE7kUn1u3X1eAkHiiKTDk1FUnWZ8I Q4A1BvHw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jNImG-0002LU-1t; Sat, 11 Apr 2020 16:14:40 +0000 Date: Sat, 11 Apr 2020 09:14:39 -0700 From: Matthew Wilcox To: syzbot Cc: darrick.wong@oracle.com, hch@infradead.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, riteshh@linux.ibm.com, syzkaller-bugs@googlegroups.com, tytso@mit.edu Subject: Re: WARNING in iomap_apply Message-ID: <20200411161439.GE21484@bombadil.infradead.org> References: <00000000000048518b05a2fef23a@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00000000000048518b05a2fef23a@google.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat, Apr 11, 2020 at 12:39:13AM -0700, syzbot wrote: > The bug was bisected to: > > commit d3b6f23f71670007817a5d59f3fbafab2b794e8c > Author: Ritesh Harjani > Date: Fri Feb 28 09:26:58 2020 +0000 > > ext4: move ext4_fiemap to use iomap framework > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16c62a57e00000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=15c62a57e00000 > console output: https://syzkaller.appspot.com/x/log.txt?x=11c62a57e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+77fa5bdb65cc39711820@syzkaller.appspotmail.com > Fixes: d3b6f23f7167 ("ext4: move ext4_fiemap to use iomap framework") > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 7023 at fs/iomap/apply.c:51 iomap_apply+0xa0c/0xcb0 fs/iomap/apply.c:51 This is: if (WARN_ON(iomap.length == 0)) return -EIO; and the call trace contains ext4_fiemap() so the syzbot bisection looks correct. > iomap_fiemap+0x184/0x2c0 fs/iomap/fiemap.c:88 > _ext4_fiemap+0x178/0x4f0 fs/ext4/extents.c:4860 > ovl_fiemap+0x13f/0x200 fs/overlayfs/inode.c:467 > ioctl_fiemap fs/ioctl.c:226 [inline] > do_vfs_ioctl+0x8d7/0x12d0 fs/ioctl.c:715