Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753152Ab2BRQ5n (ORCPT ); Sat, 18 Feb 2012 11:57:43 -0500 Received: from mail-tul01m020-f174.google.com ([209.85.214.174]:38530 "EHLO mail-tul01m020-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752803Ab2BRQ5l convert rfc822-to-8bit (ORCPT ); Sat, 18 Feb 2012 11:57:41 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of przemyslaw@pawelczyk.it designates 10.182.182.100 as permitted sender) smtp.mail=przemyslaw@pawelczyk.it MIME-Version: 1.0 Date: Sat, 18 Feb 2012 17:57:40 +0100 Message-ID: Subject: [BUG] task->nsproxy was unexpectedly NULL (caught in exit_shm) From: =?UTF-8?Q?Przemys=C5=82aw_Pawe=C5=82czyk?= To: Vasiliy Kulikov Cc: lkml Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6851 Lines: 149 Hello. Below bug hit me today when I closed one of many tabs in Chrome. The kernel is from debian wheezy current kernel package: linux-image-3.2.0-1-amd64 (v3.2.4). Feb 18 11:28:38 debian kernel: [ 3392.815292] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 Feb 18 11:28:38 debian kernel: [ 3392.815309] IP: [] exit_shm+0xa/0x54 Feb 18 11:28:38 debian kernel: [ 3392.815325] PGD 0 Feb 18 11:28:38 debian kernel: [ 3392.815331] Oops: 0000 [#1] SMP Feb 18 11:28:38 debian kernel: [ 3392.815340] CPU 0 Feb 18 11:28:38 debian kernel: [ 3392.815343] Modules linked in: pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) powernow_k8 mperf cpufreq_stats cpufreq_conservative cpufreq_userspace cpufreq_powersave parport_pc ppdev lp parport binfmt_misc nfsd nfs lockd fscache auth_rpcgss nfs_acl sunrpc kvm_amd kvm fuse ext2 loop snd_hda_codec_hdmi nvidia(P) snd_hda_intel snd_hda_codec snd_intel8x0 snd_hwdep snd_ac97_codec ac97_bus snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device snd k8temp pcspkr edac_core edac_mce_amd soundcore evdev snd_page_alloc i2c_nforce2 i2c_core processor button ext3 jbd mbcache btrfs zlib_deflate crc32c libcrc32c dm_mirror dm_region_hash dm_log dm_mod usbhid hid sr_mod cdrom sd_mod crc_t10dif ohci_hcd ata_generic ahci pata_amd libahci pata_jmicron sata_nv thermal fan thermal_sys floppy ehci_hcd libata usbcore scsi_mod forcedeth usb_common [last unloaded: scs i_wait_scan] Feb 18 11:28:38 debian kernel: [ 3392.815476] Feb 18 11:28:38 debian kernel: [ 3392.815483] Pid: 3806, comm: chrome Tainted: P O 3.2.0-1-amd64 #1 Unknow Unknow/KN9 Series(NF-CK804) Feb 18 11:28:38 debian kernel: [ 3392.815493] RIP: 0010:[] [] exit_shm+0xa/0x54 Feb 18 11:28:38 debian kernel: [ 3392.815504] RSP: 0018:ffff88012de61ce8 EFLAGS: 00010292 Feb 18 11:28:38 debian kernel: [ 3392.815509] RAX: 0000000000000000 RBX: ffff880130264300 RCX: 0000000000000008 Feb 18 11:28:38 debian kernel: [ 3392.815515] RDX: ffff88012e3b28c0 RSI: ffff88010ef96480 RDI: ffff880130264300 Feb 18 11:28:38 debian kernel: [ 3392.815520] RBP: 000000000000000f R08: ffff88012c4a3818 R09: ffff88012c4a38c8 Feb 18 11:28:38 debian kernel: [ 3392.815526] R10: ffff88012c4a3a28 R11: ffff88010ef96480 R12: ffff88010ef96480 Feb 18 11:28:38 debian kernel: [ 3392.815531] R13: ffff88012fc56600 R14: 0000000000000001 R15: 000000000000413c Feb 18 11:28:38 debian kernel: [ 3392.815538] FS: 00007f7610f2f700(0000) GS:ffff880137c00000(0000) knlGS:0000000000000000 Feb 18 11:28:38 debian kernel: [ 3392.815544] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b Feb 18 11:28:38 debian kernel: [ 3392.815549] CR2: 0000000000000010 CR3: 000000012e479000 CR4: 00000000000006f0 Feb 18 11:28:38 debian kernel: [ 3392.815556] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Feb 18 11:28:38 debian kernel: [ 3392.815561] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Feb 18 11:28:38 debian kernel: [ 3392.815568] Process chrome (pid: 3806, threadinfo ffff88012de60000, task ffff880131264300) Feb 18 11:28:38 debian kernel: [ 3392.815572] Stack: Feb 18 11:28:38 debian kernel: [ 3392.815576] 0000000000000000 ffff880130264300 000000000000000f ffffffff81049af5 Feb 18 11:28:38 debian kernel: [ 3392.815585] 000000000000192a ffff88012de61d08 ffff880131264300 ffffffff817a8508 Feb 18 11:28:38 debian kernel: [ 3392.815594] 00007f7610f2e000 ffff88010ef96480 0000000000000944 000000000000000f Feb 18 11:28:38 debian kernel: [ 3392.815604] Call Trace: Feb 18 11:28:38 debian kernel: [ 3392.815616] [] ? do_exit+0x28b/0x732 Feb 18 11:28:38 debian kernel: [ 3392.815626] [] ? do_group_exit+0x74/0x9e Feb 18 11:28:38 debian kernel: [ 3392.815635] [] ? get_signal_to_deliver+0x46d/0x48f Feb 18 11:28:38 debian kernel: [ 3392.815644] [] ? handle_pte_fault+0x739/0x79f Feb 18 11:28:38 debian kernel: [ 3392.815655] [] ? do_signal+0x38/0x610 Feb 18 11:28:38 debian kernel: [ 3392.815663] [] ? set_next_entity+0x32/0x55 Feb 18 11:28:38 debian kernel: [ 3392.815672] [] ? paravirt_write_msr+0xb/0xe Feb 18 11:28:38 debian kernel: [ 3392.815679] [] ? __switch_to+0x138/0x20e Feb 18 11:28:38 debian kernel: [ 3392.815690] [] ? sys_futex+0x138/0x148 Feb 18 11:28:38 debian kernel: [ 3392.815698] [] ? do_notify_resume+0x25/0x68 Feb 18 11:28:38 debian kernel: [ 3392.815707] [] ? int_signal+0x12/0x17 Feb 18 11:28:38 debian kernel: [ 3392.815713] Code: 48 8d bd c0 00 00 00 48 89 ea 48 c7 c6 b8 7e 15 81 e8 e9 f6 04 00 48 89 df 5b 5b 5d e9 e9 a7 f0 ff 55 53 50 48 8b 87 78 04 00 00 <48> 8b 68 10 83 bd 98 00 00 00 00 74 39 48 8d 9d a0 00 00 00 48 Feb 18 11:28:38 debian kernel: [ 3392.815783] RIP [] exit_shm+0xa/0x54 Feb 18 11:28:38 debian kernel: [ 3392.815792] RSP Feb 18 11:28:38 debian kernel: [ 3392.815795] CR2: 0000000000000010 Feb 18 11:28:38 debian kernel: [ 3392.815801] ---[ end trace 1bd7e5ff0e6f1b66 ]--- Feb 18 11:28:38 debian kernel: [ 3392.815807] Fixing recursive fault but reboot is needed! Relevant code: void exit_shm(struct task_struct *task) 311 { 0xffffffff811581b9 <+0>: 55 push %rbp 0xffffffff811581ba <+1>: 53 push %rbx 0xffffffff811581bb <+2>: 50 push %rax 312 struct ipc_namespace *ns = task->nsproxy->ipc_ns; 0xffffffff811581bc <+3>: 48 8b 87 78 04 00 00 mov 0x478(%rdi),%rax /* task->nsproxy */ 0xffffffff811581c3 <+10>: 48 8b 68 10 mov 0x10(%rax),%rbp /* ->ipc_ns */ 313 314 if (shm_ids(ns).in_use == 0) 0xffffffff811581c7 <+14>: 83 bd 98 00 00 00 00 cmpl $0x0,0x98(%rbp) 0xffffffff811581ce <+21>: 74 39 je 0xffffffff81158209 315 return; 316 317 /* Destroy all already created segments, but not mapped yet */ 318 down_write(&shm_ids(ns).rw_mutex); 0xffffffff811581d0 <+23>: 48 8d 9d a0 00 00 00 lea 0xa0(%rbp),%rbx 0xffffffff811581d7 <+30>: 48 89 df mov %rbx,%rdi 0xffffffff811581da <+33>: e8 08 7e 1e 00 callq 0xffffffff8133ffe7 ... So task->nsproxy was unexpectedly NULL atm. The bug happened only once so far. Regards. -- Przemysław Pawełczyk -- 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/