From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: NET_NS: unregister_netdevice: waiting for lo to become free (after using openvpn) Date: Thu, 05 Aug 2010 02:51:29 -0700 Message-ID: References: <20100709235744.GA12752@kroah.com> <20100710101540.2799c9ef@xenia.leun.net> <20100710140800.GA20424@kroah.com> <20100710165208.59272ae6@xenia.leun.net> <20100710235323.5336f627@xenia.leun.net> <20100711192939.1c25dcaf@xenia.leun.net> <20100804153543.56f6ecad@xenia.leun.net> <20100804214618.GA6289@kroah.com> <20100805001105.5a3453ed@xenia.leun.net> <20100805112538.60a46cb1@xenia.leun.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Greg KH , netdev@vger.kernel.org, davem@davemloft.net, linux-kernel@vger.kernel.org, Alexey Dobriyan , Patrick McHardy To: Michael Leun Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:47841 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755581Ab0HEJvf (ORCPT ); Thu, 5 Aug 2010 05:51:35 -0400 In-Reply-To: <20100805112538.60a46cb1@xenia.leun.net> (Michael Leun's message of "Thu\, 5 Aug 2010 11\:25\:38 +0200") Sender: netdev-owner@vger.kernel.org List-ID: Michael Leun writes: > Hi, > > On Wed, 04 Aug 2010 17:12:29 -0700 > ebiederm@xmission.com (Eric W. Biederman) wrote: > > First, thank you very much for picking that up (and, of course, for > your work at linux in general). > > >> > # > unshare -n /bin/bash >> > # > # how to setup veth device pair to get connectivity into >> > namespace not shown here # > openvpn --config some.config >> > [ running some traffic over vpn device not shown here ] >> > ^c # stopping openvpn >> > # > lsof -i >> > # > netstat -an >> > Active Internet connections (servers and established) >> > Proto Recv-Q Send-Q Local Address Foreign Address >> > State Active UNIX domain sockets (servers and established) >> > Proto RefCnt Flags Type State I-Node Path >> > # > ps ax|grep openvpn|grep -v grep >> > # > # cannot find anything that suggests there is anything left >> > from that openvpn session # > exit # logging out from shell in >> > network namespace >> > >> > Now I get >> > >> > Jul 10 20:02:36 doris kernel: unregister_netdevice: waiting for lo >> > to become free. Usage count = 3 [repeated] >> >> How many times? > > Unfortunately looks like indefinitely. Never watched longer so far > (rebooted soon), but I'm seeing this message now repeated every 10 secs > for ~10 minutes on a idle system. Ugh. A real bug then. These can be a pain to track down and fix. I think the last one of these I tracked down took a couple of weeks. I will start digging in when I get back from vacation. > Additionally when testing this I found another one (by accident started > my firewall script in that namespace...) - using netfilter RECENT > makes it barf. Stripped down to the essentials it looks like this: Micheal this is on 2.6.35? Alexey can you look at this BUG_ON? It looks like there has been a regression or you missed something when you did the netns conversion of xt_recent. >> # unshare -n /bin/bash >> # iptables -I INPUT -d 1.2.3.4 -m recent --name BLA --set >> # exit > > Aug 5 11:19:47 doris kernel: [ 218.420238] ------------[ cut here ]------------ > Aug 5 11:19:47 doris kernel: [ 218.420256] kernel BUG at net/netfilter/xt_recent.c:609! > Aug 5 11:19:47 doris kernel: [ 218.420268] invalid opcode: 0000 [#1] PREEMPT SMP > Aug 5 11:19:47 doris kernel: [ 218.420284] last sysfs file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0/charge_full > Aug 5 11:19:47 doris kernel: [ 218.420295] Modules linked in: snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device edd cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ipt_REJECT ipt_LOG xt_limit xt_recent iptable_mangle iptable_nat iptable_filter nf_conntrack_ipv6 xt_state xt_tcpudp ip6table_filter ip6_tables nf_nat_ftp nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack_ftp nf_conntrack ip_tables x_tables fuse nls_utf8 loop arc4 ecb iwlagn iwlcore mac80211 snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm cfg80211 snd_timer snd usb_storage iTCO_wdt soundcore tg3 sg iTCO_vendor_support snd_page_alloc rfkill i2c_i801 pcspkr battery ac ext4 jbd2 crc16 sha256_generic aes_generic cbc dm_crypt linear i915 drm_kms_helper drm i2c_algo_bit sd_mod vide o intel_agp button dm_snapshot dm_mod fan processor ata_piix ahci libahci libata scsi_mod thermal thermal_sys > Aug 5 11:19:47 doris kernel: [ 218.420529] > Aug 5 11:19:47 doris kernel: [ 218.420542] Pid: 13, comm: netns Not tainted 2.6.35 #2 Kuril /40684JG > Aug 5 11:19:47 doris kernel: [ 218.420557] EIP: 0060:[] EFLAGS: 00010206 CPU: 0 > Aug 5 11:19:47 doris kernel: [ 218.420578] EIP is at recent_net_exit+0x55/0x70 [xt_recent] > Aug 5 11:19:47 doris kernel: [ 218.420589] EAX: f2218000 EBX: f5b79290 ECX: f2f27b40 EDX: f5cd4000 > Aug 5 11:19:47 doris kernel: [ 218.420601] ESI: f2218000 EDI: f5cd5f44 EBP: f5cd5f28 ESP: f5cd5f20 > Aug 5 11:19:47 doris kernel: [ 218.420612] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 > Aug 5 11:19:47 doris kernel: [ 218.420626] Process netns (pid: 13, ti=f5cd4000 task=f5cc9920 task.ti=f5cd4000) > Aug 5 11:19:47 doris kernel: [ 218.420635] Stack: > Aug 5 11:19:47 doris kernel: [ 218.420641] f5cd5f30 fc887618 f5cd5f3c c130867d fc887618 f5cd5f44 c1308850 f5cd5f60 > Aug 5 11:19:47 doris kernel: [ 218.420667] <0> c1308919 f2218014 f2218014 f221800c f221800c c15915a0 c3bb4f40 c1308850 > Aug 5 11:19:47 doris kernel: [ 218.420695] <0> f5cd5fbc c105a230 c13d1658 00000001 00000000 f7048000 c160f500 f5cc9c00 > Aug 5 11:19:47 doris kernel: [ 218.420724] Call Trace: > Aug 5 11:19:47 doris kernel: [ 218.420749] [] ? ops_exit_list+0x1d/0x50 > Aug 5 11:19:47 doris kernel: [ 218.420766] [] ? cleanup_net+0x0/0x160 > Aug 5 11:19:47 doris kernel: [ 218.420782] [] ? cleanup_net+0xc9/0x160 > Aug 5 11:19:47 doris kernel: [ 218.420797] [] ? cleanup_net+0x0/0x160 > Aug 5 11:19:47 doris kernel: [ 218.420815] [] ? worker_thread+0x110/0x250 > Aug 5 11:19:47 doris kernel: [ 218.420832] [] ? schedule+0x748/0x7a0 > Aug 5 11:19:47 doris kernel: [ 218.420849] [] ? autoremove_wake_function+0x0/0x40 > Aug 5 11:19:47 doris kernel: [ 218.420864] [] ? worker_thread+0x0/0x250 > Aug 5 11:19:47 doris kernel: [ 218.420879] [] ? kthread+0x6c/0x80 > Aug 5 11:19:47 doris kernel: [ 218.420895] [] ? kthread+0x0/0x80 > Aug 5 11:19:47 doris kernel: [ 218.420910] [] ? kernel_thread_helper+0x6/0x10 > Aug 5 11:19:47 doris kernel: [ 218.420919] Code: 91 08 89 e2 81 e2 00 e0 ff ff 83 6a 14 01 f6 42 08 08 75 19 3b 1b 75 13 ba fa 72 88 fc e8 94 3e 8c c4 8d 64 24 04 5b 5d c3 0f 0b <0f> 0b 89 45 f8 e8 a1 ad b4 c4 8b 45 f8 eb da 8d b6 00 00 00 00 > Aug 5 11:19:47 doris kernel: [ 218.421063] EIP: [] recent_net_exit+0x55/0x70 [xt_recent] SS:ESP 0068:f5cd5f20 > Aug 5 11:19:47 doris kernel: [ 218.421136] ---[ end trace f57524f15f4df616 ]--- > Eric