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=-1.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 4E68FC43441 for ; Sat, 17 Nov 2018 13:36:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BFEC20818 for ; Sat, 17 Nov 2018 13:36:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="VC3Li+kY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0BFEC20818 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726505AbeKQXxK (ORCPT ); Sat, 17 Nov 2018 18:53:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:41374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726020AbeKQXxK (ORCPT ); Sat, 17 Nov 2018 18:53:10 -0500 Received: from tleilax.poochiereds.net (cpe-71-70-156-158.nc.res.rr.com [71.70.156.158]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A8A6920815; Sat, 17 Nov 2018 13:36:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542461787; bh=fvTaDa6YrAUeIj12DCaFAmzV+gt817/48vJLaARFNik=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=VC3Li+kYZrFDPYrsxSKipojOBerD8hrWOu2n0p225GQXT3pdUm5tsuEAF1hHEhZpc mPzES6HmD3IlT/yO7ou3ruCrhZsW61bsnJjf7gb+VSfxoSd8DDcT401a6iI0r9Lstn IJtS9ceDXXRjNL+hAxiQSZd8Sh66IlQc6R4O2hv8= Message-ID: Subject: Re: KASAN: stack-out-of-bounds Read in locks_remove_flock From: Jeff Layton To: Dmitry Vyukov , syzbot Cc: Bruce Fields , linux-fsdevel , LKML , syzkaller-bugs@googlegroups.com, Al Viro , NeilBrown Date: Sat, 17 Nov 2018 08:36:25 -0500 In-Reply-To: References: <00000000000082cc8d057a0c0877@google.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-2.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2018-11-16 at 12:40 -0800, Dmitry Vyukov wrote: > On Tue, Nov 6, 2018 at 9:03 PM, syzbot > wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: d881de30d29e Add linux-next specific files for 20181107 > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=14aa485d400000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=caa433e1c8778437 > > dashboard link: https://syzkaller.appspot.com/bug?extid=1818cd833edc063452c6 > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+1818cd833edc063452c6@syzkaller.appspotmail.com > > This is another manifestation of the following report, right? > > #syz dup: KASAN: use-after-free Read in locks_delete_block > Slightly different manifestation in this case, but the same bug, yes. > > ================================================================== > > BUG: KASAN: stack-out-of-bounds in locks_remove_flock+0x33c/0x350 > > fs/locks.c:2567 > > Read of size 8 at addr ffff8801c71c7a08 by task syz-executor5/20562 > > > > CPU: 0 PID: 20562 Comm: syz-executor5 Not tainted 4.20.0-rc1-next-20181107+ > > #107 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > Call Trace: > > __dump_stack lib/dump_stack.c:77 [inline] > > dump_stack+0x244/0x39d lib/dump_stack.c:113 > > print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 > > kasan_report_error mm/kasan/report.c:354 [inline] > > kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 > > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > > locks_remove_flock+0x33c/0x350 fs/locks.c:2567 > > locks_remove_file+0x148/0x5c0 fs/locks.c:2607 > > __fput+0x2f0/0xa70 fs/file_table.c:271 > > ____fput+0x15/0x20 fs/file_table.c:312 > > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > > exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 > > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > RIP: 0033:0x411021 > > Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 34 19 00 00 c3 48 > > 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 > > c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 > > RSP: 002b:00007ffdb42509a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 > > RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000411021 > > RDX: 0000000000000000 RSI: 0000000000732ea0 RDI: 0000000000000004 > > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > > R10: 00007ffdb42508c0 R11: 0000000000000293 R12: 0000000000000000 > > R13: 0000000000000001 R14: 0000000000000201 R15: 0000000000000005 > > > > The buggy address belongs to the page: > > page:ffffea00071c71c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 > > flags: 0x2fffc0000000000() > > raw: 02fffc0000000000 0000000000000000 ffffffff071c0101 0000000000000000 > > raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 > > page dumped because: kasan: bad access detected > > > > Memory state around the buggy address: > > ffff8801c71c7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > ffff8801c71c7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > > > > ffff8801c71c7a00: f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > > ^ > > ffff8801c71c7a80: 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2 f2 f2 f8 f2 f2 > > ffff8801c71c7b00: f2 f2 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 00 00 > > ================================================================== > > > > > > --- > > This bug is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ for more information about syzbot. > > syzbot engineers can be reached at syzkaller@googlegroups.com. > > > > syzbot will keep track of this bug report. See: > > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > > syzbot. > > > > -- > > You received this message because you are subscribed to the Google Groups > > "syzkaller-bugs" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to syzkaller-bugs+unsubscribe@googlegroups.com. > > To view this discussion on the web visit > > https://groups.google.com/d/msgid/syzkaller-bugs/00000000000082cc8d057a0c0877%40google.com. > > For more options, visit https://groups.google.com/d/optout. -- Jeff Layton