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=-0.8 required=3.0 tests=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 F17C9C2BA16 for ; Sat, 4 Apr 2020 06:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A7C8206B8 for ; Sat, 4 Apr 2020 06:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725995AbgDDGOI (ORCPT ); Sat, 4 Apr 2020 02:14:08 -0400 Received: from mail.parknet.co.jp ([210.171.160.6]:36796 "EHLO mail.parknet.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725536AbgDDGOI (ORCPT ); Sat, 4 Apr 2020 02:14:08 -0400 Received: from ibmpc.myhome.or.jp (server.parknet.ne.jp [210.171.168.39]) by mail.parknet.co.jp (Postfix) with ESMTPSA id 0FE2A12F211; Sat, 4 Apr 2020 15:14:07 +0900 (JST) Received: from devron.myhome.or.jp (foobar@devron.myhome.or.jp [192.168.0.3]) by ibmpc.myhome.or.jp (8.15.2/8.15.2/Debian-18) with ESMTPS id 0346E5Hb047956 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Sat, 4 Apr 2020 15:14:06 +0900 Received: from devron.myhome.or.jp (foobar@localhost [127.0.0.1]) by devron.myhome.or.jp (8.15.2/8.15.2/Debian-18) with ESMTPS id 0346E5xb200873 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Sat, 4 Apr 2020 15:14:05 +0900 Received: (from hirofumi@localhost) by devron.myhome.or.jp (8.15.2/8.15.2/Submit) id 0346E2M4200872; Sat, 4 Apr 2020 15:14:02 +0900 From: OGAWA Hirofumi To: Dmitry Vyukov Cc: syzbot , Marco Elver , LKML , syzkaller-bugs Subject: Re: KCSAN: data-race in __fat_write_inode / fat12_ent_get References: <0000000000000cfff005a26226ce@google.com> <874ku0sncc.fsf@mail.parknet.co.jp> Date: Sat, 04 Apr 2020 15:14:02 +0900 In-Reply-To: (Dmitry Vyukov's message of "Fri, 3 Apr 2020 18:36:26 +0200") Message-ID: <877dyveq1h.fsf@mail.parknet.co.jp> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dmitry Vyukov writes: > On Fri, Apr 3, 2020 at 3:36 PM OGAWA Hirofumi > wrote: >> >> Hm, looks like the race between a directory entry vs a FAT entry. This >> bug was happened with the corrupted image? Or the image passes the check >> of dosfsck? >> >> If the corrupted image, it may be hard to prevent the all races. Well, >> anyway, the corrupted image of the report will help to detect this >> corruption. > > From the log, it's this program. > My bet on a corrupted image. syzkaller does not have format > descriptions for fat, so it's just random bytes. You meant I can regenerate a disk image from that log (if so, how)? If not, for next time, it would be helpful if syzkaller provides the log to regenerate the corrupted image (or saving a corrupted image) to reproduce this, then I can try to detect the corruption pattern early. Thanks. -- OGAWA Hirofumi