Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752927AbaDXTfj (ORCPT ); Thu, 24 Apr 2014 15:35:39 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:41231 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752758AbaDXTfe (ORCPT ); Thu, 24 Apr 2014 15:35:34 -0400 Message-ID: <5359677F.6000005@oracle.com> Date: Thu, 24 Apr 2014 15:35:27 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Greg KH CC: linux-usb@vger.kernel.org, Dave Jones , LKML Subject: Re: usb: mon: freeing active timer References: <53594C7E.1080407@oracle.com> <20140424192406.GA6054@kroah.com> In-Reply-To: <20140424192406.GA6054@kroah.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/24/2014 03:24 PM, Greg KH wrote: > On Thu, Apr 24, 2014 at 01:40:14PM -0400, Sasha Levin wrote: >> > Hi all, >> > >> > While fuzzing with trinity inside a KVM tools guest running the latest -next >> > kernel I've stumbled on the following: >> > >> > [ 1361.390880] WARNING: CPU: 10 PID: 24274 at lib/debugobjects.c:260 debug_print_object+0x8c/0xb0() >> > [ 1361.391203] ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x20 >> > [ 1361.391203] Modules linked in: >> > [ 1361.391203] CPU: 10 PID: 24274 Comm: trinity-c83 Not tainted 3.15.0-rc2-next-20140423-sasha-00018-gc4ff6c4 #408 >> > [ 1361.391203] 0000000000000009 ffff8801de341c78 ffffffffb85271f2 0000000000000001 >> > [ 1361.391203] ffff8801de341cc8 ffff8801de341cb8 ffffffffb515afcc ffff8801eb3ebd98 >> > [ 1361.391203] ffff8801eb751870 ffffffffb9e76200 ffffffffb98dc502 ffffffffbc702550 >> > [ 1361.391203] Call Trace: >> > [ 1361.391203] dump_stack (lib/dump_stack.c:52) >> > [ 1361.391203] warn_slowpath_common (kernel/panic.c:430) >> > [ 1361.391203] warn_slowpath_fmt (kernel/panic.c:445) >> > [ 1361.391203] debug_print_object (lib/debugobjects.c:262) >> > [ 1361.391203] ? __queue_work (kernel/workqueue.c:1452) >> > [ 1361.391203] __debug_check_no_obj_freed (lib/debugobjects.c:697) >> > [ 1361.391203] debug_check_no_obj_freed (lib/debugobjects.c:726) >> > [ 1361.391203] kmem_cache_free (mm/slub.c:2689 mm/slub.c:2717) >> > [ 1361.391203] ? kmem_cache_destroy (mm/slab_common.c:363) >> > [ 1361.391203] kmem_cache_destroy (mm/slab_common.c:363) >> > [ 1361.391203] mon_text_release (drivers/usb/mon/mon_text.c:643) >> > [ 1361.391203] __fput (fs/file_table.c:217) >> > [ 1361.391203] ____fput (fs/file_table.c:253) >> > [ 1361.391203] task_work_run (kernel/task_work.c:125 (discriminator 1)) >> > [ 1361.391203] do_notify_resume (include/linux/tracehook.h:196 arch/x86/kernel/signal.c:751) >> > [ 1361.391203] int_signal (arch/x86/kernel/entry_64.S:807) > So you were running usbmon at the time? Were you actually monitoring a > specific USB device/bus, or something else? This was inside a vm with no actual physical USB devices: # lsusb -t lsusb: cannot open "/var/lib/usbutils/usb.ids", No such file or directory /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ozwpan/8p, 12M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dummy_hcd/1p, 480M |__ Port 1: Dev 2, If 0, Class=comm., Driver=cdc_eem, 480M Since it happened while I was fuzzing, I'm not sure what exactly was getting monitored at that point. Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/