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Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71

Started byKees Cook <keescook@chromium.org>
First post2016-09-06 17:50 +0200
Last post2016-09-08 18:00 +0200
Articles 5 — 2 participants

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  Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71 Kees Cook <keescook@chromium.org> - 2016-09-06 17:50 +0200
    Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60  __list_del_entry+0x4d/0x71 "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-09-07 09:40 +0200
      Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71 Kees Cook <keescook@chromium.org> - 2016-09-07 19:30 +0200
        Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60  __list_del_entry+0x4d/0x71 "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-09-08 11:30 +0200
          Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71 Kees Cook <keescook@chromium.org> - 2016-09-08 18:00 +0200

#1477561 — Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71

FromKees Cook <keescook@chromium.org>
Date2016-09-06 17:50 +0200
SubjectRe: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
Message-ID<seqNj-3PR-9@gated-at.bofh.it>
On Sun, Sep 4, 2016 at 5:48 AM, Paul E. McKenney
<paulmck@linux.vnet.ibm.com> wrote:
> On Sun, Sep 04, 2016 at 08:35:40AM +0800, kernel test robot wrote:
>>
>> FYI, we noticed the following commit:
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2016.08.19a
>> commit 8052ce2d9771ab5a818307f3abbaf33bba82a631 ("list: Split list_add() debug checking into separate function")
>>
>> in testcase: boot
>>
>> on test machine: qemu-system-i386 -enable-kvm -m 360M
>>
>> caused below changes:
>
> Hello, Kees,
>
> Looks like your change might have actually found a bug.  ;-)
>
> How would you like to handle this?

We should fix the bug! :)

>
>                                                         Thanx, Paul
>
>> +------------------------------------------------------------+------------+------------+
>> |                                                            | 0a33d912a3 | 8052ce2d97 |
>> +------------------------------------------------------------+------------+------------+
>> | boot_successes                                             | 0          | 0          |
>> | boot_failures                                              | 211        | 18         |
>> | WARNING:at_lib/list_debug.c:#__list_del_entry              | 211        | 18         |
>> | calltrace:init                                             | 209        | 18         |
>> | WARNING:at_lib/list_debug.c:#__list_add                    | 209        |            |
>> | calltrace:i8042_init                                       | 209        | 17         |
>> | calltrace:SyS_reboot                                       | 192        | 4          |
>> | EIP_is_at__mutex_unlock_slowpath                           | 29         |            |
>> | Kernel_panic-not_syncing:softlockup:hung_tasks             | 138        |            |
>> | BUG:workqueue_lockup-pool_cpus=#flags=#nice=#stuck_for#s   | 56         |            |
>> | EIP_is_at_lock_release                                     | 7          |            |
>> | EIP_is_at_lock_acquire                                     | 28         |            |
>> | EIP_is_at_raw_spin_unlock_irq                              | 30         |            |
>> | EIP_is_at_mutex_lock_nested                                | 21         |            |
>> | EIP_is_at_lock_is_held                                     | 10         |            |
>> | EIP_is_at_device_shutdown                                  | 3          |            |
>> | EIP_is_at___might_sleep                                    | 5          |            |
>> | EIP_is_at__list_del_entry                                  | 4          | 1          |
>> | EIP_is_at_get_device                                       | 1          |            |
>> | BUG:unable_to_handle_kernel                                | 7          | 5          |
>> | Oops                                                       | 7          | 5          |
>> | calltrace:SyS_ipc                                          | 4          | 4          |
>> | Kernel_panic-not_syncing:Fatal_exception                   | 7          | 5          |
>> | EIP_is_at_pm_runtime_barrier                               | 1          |            |
>> | EIP_is_at_lock_acquired                                    | 1          |            |
>> | EIP_is_at__might_sleep                                     | 1          |            |
>> | BUG:workqueue_lockup-pool_cpus=#-#flags=#nice=#stuck_for#s | 1          |            |
>> | WARNING:at_arch/x86/mm/dump_pagetables.c:#note_page        | 26         |            |
>> | calltrace:mark_rodata_ro                                   | 26         |            |
>> | WARNING:at_lib/list_debug.c:#__list_add_valid              | 0          | 17         |
>> | calltrace:serio_handle_event                               | 0          | 17         |
>> | calltrace:userio_misc_init                                 | 0          | 17         |
>> | calltrace:mousedev_init                                    | 0          | 17         |
>> | calltrace:evdev_init                                       | 0          | 17         |
>> | calltrace:cmos_init                                        | 0          | 17         |
>> | calltrace:test_init                                        | 0          | 17         |
>> | calltrace:pca_isa_driver_init                              | 0          | 17         |
>> | calltrace:vim2m_init                                       | 0          | 17         |
>> | calltrace:fm_drv_init                                      | 0          | 17         |
>> | calltrace:test_power_init                                  | 0          | 17         |
>> | calltrace:raid#_init                                       | 0          | 17         |
>> | calltrace:dm_init                                          | 0          | 17         |
>> | calltrace:vhci_init                                        | 0          | 17         |
>> | calltrace:dcdrbu_init                                      | 0          | 17         |
>> | calltrace:dcdbas_init                                      | 0          | 17         |
>> | calltrace:uhid_init                                        | 0          | 17         |
>> | calltrace:vhost_net_init                                   | 0          | 17         |
>> | calltrace:dummy_stm_init                                   | 0          | 17         |
>> | calltrace:stm_heartbeat_init                               | 0          | 17         |
>> | calltrace:binder_init                                      | 0          | 17         |
>> | calltrace:teql_init                                        | 0          | 17         |
>> | calltrace:ipip_init                                        | 0          | 17         |
>> | calltrace:ipgre_init                                       | 0          | 17         |
>> | calltrace:sit_init                                         | 0          | 17         |
>> | calltrace:ip6_tunnel_init                                  | 0          | 17         |
>> | calltrace:ip6gre_init                                      | 0          | 17         |
>> | calltrace:irlan_init                                       | 0          | 17         |
>> | calltrace:pm_qos_power_init                                | 0          | 17         |
>> | calltrace:ubi_init                                         | 0          | 17         |
>> | calltrace:SyS_setsockopt                                   | 0          | 2          |
>> | calltrace:SyS_socketcall                                   | 0          | 2          |
>> | WARNING:at_include/linux/kref.h:#kobject_get               | 0          | 4          |
>> | WARNING:at_kernel/locking/lockdep.c:#__lock_acquire        | 0          | 4          |
>> | BUG:kernel_hang_in_test_stage                              | 0          | 4          |
>> | calltrace:fw_cfg_sysfs_init                                | 0          | 7          |
>> +------------------------------------------------------------+------------+------------+
>>
>>
>>
>> [  152.680291] g_acm_ms usbip-vudc.0: failed to start g_acm_ms: -22
>> [  152.689209] usbip-vudc: probe of usbip-vudc.0 failed with error -22
>> [  152.698509] ------------[ cut here ]------------
>> [  152.709786] WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
>> [  152.722785] list_del corruption. next->prev should be cc0230d4, but was 6b6b6b6b

That's the poison value, so this is a remove-after-remove bug?

>> [  152.732828] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc1-00033-g8052ce2 #1
>> [  152.742576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
>> [  152.754081]  00000000 00200246 c0033e78 c13c456b c0033ea4 c13e72ac c0033e90 c103fd02
>> [  152.765720]  0000003c 6b6b6b6b cc0230d4 cc02300c c0033eac c103fd41 00000009 00000000
>> [  152.776864]  c0033ea4 c1f7bc14 c0033ec0 c0033ecc c13e72ac c1f7bace 0000003c c1f7bc14
>> [  152.788472] Call Trace:
>> [  152.791964]  [<c13c456b>] dump_stack+0x75/0xa9
>> [  152.797835]  [<c13e72ac>] ? __list_del_entry+0x4d/0x71
>> [  152.804221]  [<c103fd02>] __warn+0xad/0xc4
>> [  152.809694]  [<c103fd41>] warn_slowpath_fmt+0x28/0x2d
>> [  152.816501]  [<c13e72ac>] __list_del_entry+0x4d/0x71
>> [  152.822946]  [<c15027a8>] device_pm_remove+0x2b/0x5a
>> [  152.829560]  [<c14f6317>] device_del+0x134/0x19a
>> [  152.835558]  [<c14f5c38>] ? dev_set_name+0x14/0x16
>> [  152.842135]  [<c14f9d7c>] platform_device_del+0x16/0x5d
>> [  152.848909]  [<c2207515>] init+0xe5/0x112
>> [  152.854149]  [<c2207430>] ? usbip_host_init+0xe5/0xe5

What device is this? Looks like it's being removed right at init time??

>> [  152.860796]  [<c21cec35>] do_one_initcall+0x7e/0x101
>> [  152.867316]  [<c10564b7>] ? parse_args+0x190/0x265
>> [  152.873497]  [<c21ced88>] ? kernel_init_freeable+0xd0/0x174
>> [  152.880923]  [<c21ceda4>] kernel_init_freeable+0xec/0x174
>> [  152.887499]  [<c1be421b>] kernel_init+0x8/0xd0
>> [  152.893658]  [<c1bec3ae>] ret_from_kernel_thread+0xe/0x30
>> [  152.900759]  [<c1be4213>] ? rest_init+0x111/0x111
>> [  152.907334] ---[ end trace 2003739b08d25430 ]---
>> [  152.920040] ------------[ cut here ]------------

-Kees


-- 
Kees Cook
Nexus Security

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#1478023 — Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71

From"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Date2016-09-07 09:40 +0200
SubjectRe: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
Message-ID<seFCG-59y-21@gated-at.bofh.it>
In reply to#1477561
On Tue, Sep 06, 2016 at 11:49:04AM -0400, Kees Cook wrote:
> On Sun, Sep 4, 2016 at 5:48 AM, Paul E. McKenney
> <paulmck@linux.vnet.ibm.com> wrote:
> > On Sun, Sep 04, 2016 at 08:35:40AM +0800, kernel test robot wrote:
> >>
> >> FYI, we noticed the following commit:
> >>
> >> https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2016.08.19a
> >> commit 8052ce2d9771ab5a818307f3abbaf33bba82a631 ("list: Split list_add() debug checking into separate function")
> >>
> >> in testcase: boot
> >>
> >> on test machine: qemu-system-i386 -enable-kvm -m 360M
> >>
> >> caused below changes:
> >
> > Hello, Kees,
> >
> > Looks like your change might have actually found a bug.  ;-)
> >
> > How would you like to handle this?
> 
> We should fix the bug! :)

But of course...

The question is whether I am considered to be fully responsible for
chasing down any bugs that arise.  It is looking like I am, in which
case I must defer this patch to the 4.10 merge window.  Things are a
bit crazy now due to prior overcommitments...

Yes, yes, they will be crazy then as well, but this would be higher
on the priority list.

							Thanx, Paul

> >> +------------------------------------------------------------+------------+------------+
> >> |                                                            | 0a33d912a3 | 8052ce2d97 |
> >> +------------------------------------------------------------+------------+------------+
> >> | boot_successes                                             | 0          | 0          |
> >> | boot_failures                                              | 211        | 18         |
> >> | WARNING:at_lib/list_debug.c:#__list_del_entry              | 211        | 18         |
> >> | calltrace:init                                             | 209        | 18         |
> >> | WARNING:at_lib/list_debug.c:#__list_add                    | 209        |            |
> >> | calltrace:i8042_init                                       | 209        | 17         |
> >> | calltrace:SyS_reboot                                       | 192        | 4          |
> >> | EIP_is_at__mutex_unlock_slowpath                           | 29         |            |
> >> | Kernel_panic-not_syncing:softlockup:hung_tasks             | 138        |            |
> >> | BUG:workqueue_lockup-pool_cpus=#flags=#nice=#stuck_for#s   | 56         |            |
> >> | EIP_is_at_lock_release                                     | 7          |            |
> >> | EIP_is_at_lock_acquire                                     | 28         |            |
> >> | EIP_is_at_raw_spin_unlock_irq                              | 30         |            |
> >> | EIP_is_at_mutex_lock_nested                                | 21         |            |
> >> | EIP_is_at_lock_is_held                                     | 10         |            |
> >> | EIP_is_at_device_shutdown                                  | 3          |            |
> >> | EIP_is_at___might_sleep                                    | 5          |            |
> >> | EIP_is_at__list_del_entry                                  | 4          | 1          |
> >> | EIP_is_at_get_device                                       | 1          |            |
> >> | BUG:unable_to_handle_kernel                                | 7          | 5          |
> >> | Oops                                                       | 7          | 5          |
> >> | calltrace:SyS_ipc                                          | 4          | 4          |
> >> | Kernel_panic-not_syncing:Fatal_exception                   | 7          | 5          |
> >> | EIP_is_at_pm_runtime_barrier                               | 1          |            |
> >> | EIP_is_at_lock_acquired                                    | 1          |            |
> >> | EIP_is_at__might_sleep                                     | 1          |            |
> >> | BUG:workqueue_lockup-pool_cpus=#-#flags=#nice=#stuck_for#s | 1          |            |
> >> | WARNING:at_arch/x86/mm/dump_pagetables.c:#note_page        | 26         |            |
> >> | calltrace:mark_rodata_ro                                   | 26         |            |
> >> | WARNING:at_lib/list_debug.c:#__list_add_valid              | 0          | 17         |
> >> | calltrace:serio_handle_event                               | 0          | 17         |
> >> | calltrace:userio_misc_init                                 | 0          | 17         |
> >> | calltrace:mousedev_init                                    | 0          | 17         |
> >> | calltrace:evdev_init                                       | 0          | 17         |
> >> | calltrace:cmos_init                                        | 0          | 17         |
> >> | calltrace:test_init                                        | 0          | 17         |
> >> | calltrace:pca_isa_driver_init                              | 0          | 17         |
> >> | calltrace:vim2m_init                                       | 0          | 17         |
> >> | calltrace:fm_drv_init                                      | 0          | 17         |
> >> | calltrace:test_power_init                                  | 0          | 17         |
> >> | calltrace:raid#_init                                       | 0          | 17         |
> >> | calltrace:dm_init                                          | 0          | 17         |
> >> | calltrace:vhci_init                                        | 0          | 17         |
> >> | calltrace:dcdrbu_init                                      | 0          | 17         |
> >> | calltrace:dcdbas_init                                      | 0          | 17         |
> >> | calltrace:uhid_init                                        | 0          | 17         |
> >> | calltrace:vhost_net_init                                   | 0          | 17         |
> >> | calltrace:dummy_stm_init                                   | 0          | 17         |
> >> | calltrace:stm_heartbeat_init                               | 0          | 17         |
> >> | calltrace:binder_init                                      | 0          | 17         |
> >> | calltrace:teql_init                                        | 0          | 17         |
> >> | calltrace:ipip_init                                        | 0          | 17         |
> >> | calltrace:ipgre_init                                       | 0          | 17         |
> >> | calltrace:sit_init                                         | 0          | 17         |
> >> | calltrace:ip6_tunnel_init                                  | 0          | 17         |
> >> | calltrace:ip6gre_init                                      | 0          | 17         |
> >> | calltrace:irlan_init                                       | 0          | 17         |
> >> | calltrace:pm_qos_power_init                                | 0          | 17         |
> >> | calltrace:ubi_init                                         | 0          | 17         |
> >> | calltrace:SyS_setsockopt                                   | 0          | 2          |
> >> | calltrace:SyS_socketcall                                   | 0          | 2          |
> >> | WARNING:at_include/linux/kref.h:#kobject_get               | 0          | 4          |
> >> | WARNING:at_kernel/locking/lockdep.c:#__lock_acquire        | 0          | 4          |
> >> | BUG:kernel_hang_in_test_stage                              | 0          | 4          |
> >> | calltrace:fw_cfg_sysfs_init                                | 0          | 7          |
> >> +------------------------------------------------------------+------------+------------+
> >>
> >>
> >>
> >> [  152.680291] g_acm_ms usbip-vudc.0: failed to start g_acm_ms: -22
> >> [  152.689209] usbip-vudc: probe of usbip-vudc.0 failed with error -22
> >> [  152.698509] ------------[ cut here ]------------
> >> [  152.709786] WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
> >> [  152.722785] list_del corruption. next->prev should be cc0230d4, but was 6b6b6b6b
> 
> That's the poison value, so this is a remove-after-remove bug?
> 
> >> [  152.732828] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc1-00033-g8052ce2 #1
> >> [  152.742576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
> >> [  152.754081]  00000000 00200246 c0033e78 c13c456b c0033ea4 c13e72ac c0033e90 c103fd02
> >> [  152.765720]  0000003c 6b6b6b6b cc0230d4 cc02300c c0033eac c103fd41 00000009 00000000
> >> [  152.776864]  c0033ea4 c1f7bc14 c0033ec0 c0033ecc c13e72ac c1f7bace 0000003c c1f7bc14
> >> [  152.788472] Call Trace:
> >> [  152.791964]  [<c13c456b>] dump_stack+0x75/0xa9
> >> [  152.797835]  [<c13e72ac>] ? __list_del_entry+0x4d/0x71
> >> [  152.804221]  [<c103fd02>] __warn+0xad/0xc4
> >> [  152.809694]  [<c103fd41>] warn_slowpath_fmt+0x28/0x2d
> >> [  152.816501]  [<c13e72ac>] __list_del_entry+0x4d/0x71
> >> [  152.822946]  [<c15027a8>] device_pm_remove+0x2b/0x5a
> >> [  152.829560]  [<c14f6317>] device_del+0x134/0x19a
> >> [  152.835558]  [<c14f5c38>] ? dev_set_name+0x14/0x16
> >> [  152.842135]  [<c14f9d7c>] platform_device_del+0x16/0x5d
> >> [  152.848909]  [<c2207515>] init+0xe5/0x112
> >> [  152.854149]  [<c2207430>] ? usbip_host_init+0xe5/0xe5
> 
> What device is this? Looks like it's being removed right at init time??
> 
> >> [  152.860796]  [<c21cec35>] do_one_initcall+0x7e/0x101
> >> [  152.867316]  [<c10564b7>] ? parse_args+0x190/0x265
> >> [  152.873497]  [<c21ced88>] ? kernel_init_freeable+0xd0/0x174
> >> [  152.880923]  [<c21ceda4>] kernel_init_freeable+0xec/0x174
> >> [  152.887499]  [<c1be421b>] kernel_init+0x8/0xd0
> >> [  152.893658]  [<c1bec3ae>] ret_from_kernel_thread+0xe/0x30
> >> [  152.900759]  [<c1be4213>] ? rest_init+0x111/0x111
> >> [  152.907334] ---[ end trace 2003739b08d25430 ]---
> >> [  152.920040] ------------[ cut here ]------------
> 
> -Kees
> 
> 
> -- 
> Kees Cook
> Nexus Security
> 

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#1478520

FromKees Cook <keescook@chromium.org>
Date2016-09-07 19:30 +0200
Message-ID<seOPD-2Ez-19@gated-at.bofh.it>
In reply to#1478023
On Wed, Sep 7, 2016 at 12:31 AM, Paul E. McKenney
<paulmck@linux.vnet.ibm.com> wrote:
> On Tue, Sep 06, 2016 at 11:49:04AM -0400, Kees Cook wrote:
>> On Sun, Sep 4, 2016 at 5:48 AM, Paul E. McKenney
>> <paulmck@linux.vnet.ibm.com> wrote:
>> > On Sun, Sep 04, 2016 at 08:35:40AM +0800, kernel test robot wrote:
>> >>
>> >> FYI, we noticed the following commit:
>> >>
>> >> https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2016.08.19a
>> >> commit 8052ce2d9771ab5a818307f3abbaf33bba82a631 ("list: Split list_add() debug checking into separate function")
>> >>
>> >> in testcase: boot
>> >>
>> >> on test machine: qemu-system-i386 -enable-kvm -m 360M
>> >>
>> >> caused below changes:
>> >
>> > Hello, Kees,
>> >
>> > Looks like your change might have actually found a bug.  ;-)
>> >
>> > How would you like to handle this?
>>
>> We should fix the bug! :)
>
> But of course...
>
> The question is whether I am considered to be fully responsible for
> chasing down any bugs that arise.  It is looking like I am, in which
> case I must defer this patch to the 4.10 merge window.  Things are a
> bit crazy now due to prior overcommitments...

I'm going to double-check the code, but the changes I made shouldn't
have changed any of the logical checks under CONFIG_DEBUG_LIST... just
the manifestation of WARN vs BUG. So, since both this and the BPF RCU
bug have appeared, something has changed... I will go digging...

-Kees

>
> Yes, yes, they will be crazy then as well, but this would be higher
> on the priority list.
>
>                                                         Thanx, Paul
>
>> >> +------------------------------------------------------------+------------+------------+
>> >> |                                                            | 0a33d912a3 | 8052ce2d97 |
>> >> +------------------------------------------------------------+------------+------------+
>> >> | boot_successes                                             | 0          | 0          |
>> >> | boot_failures                                              | 211        | 18         |
>> >> | WARNING:at_lib/list_debug.c:#__list_del_entry              | 211        | 18         |
>> >> | calltrace:init                                             | 209        | 18         |
>> >> | WARNING:at_lib/list_debug.c:#__list_add                    | 209        |            |
>> >> | calltrace:i8042_init                                       | 209        | 17         |
>> >> | calltrace:SyS_reboot                                       | 192        | 4          |
>> >> | EIP_is_at__mutex_unlock_slowpath                           | 29         |            |
>> >> | Kernel_panic-not_syncing:softlockup:hung_tasks             | 138        |            |
>> >> | BUG:workqueue_lockup-pool_cpus=#flags=#nice=#stuck_for#s   | 56         |            |
>> >> | EIP_is_at_lock_release                                     | 7          |            |
>> >> | EIP_is_at_lock_acquire                                     | 28         |            |
>> >> | EIP_is_at_raw_spin_unlock_irq                              | 30         |            |
>> >> | EIP_is_at_mutex_lock_nested                                | 21         |            |
>> >> | EIP_is_at_lock_is_held                                     | 10         |            |
>> >> | EIP_is_at_device_shutdown                                  | 3          |            |
>> >> | EIP_is_at___might_sleep                                    | 5          |            |
>> >> | EIP_is_at__list_del_entry                                  | 4          | 1          |
>> >> | EIP_is_at_get_device                                       | 1          |            |
>> >> | BUG:unable_to_handle_kernel                                | 7          | 5          |
>> >> | Oops                                                       | 7          | 5          |
>> >> | calltrace:SyS_ipc                                          | 4          | 4          |
>> >> | Kernel_panic-not_syncing:Fatal_exception                   | 7          | 5          |
>> >> | EIP_is_at_pm_runtime_barrier                               | 1          |            |
>> >> | EIP_is_at_lock_acquired                                    | 1          |            |
>> >> | EIP_is_at__might_sleep                                     | 1          |            |
>> >> | BUG:workqueue_lockup-pool_cpus=#-#flags=#nice=#stuck_for#s | 1          |            |
>> >> | WARNING:at_arch/x86/mm/dump_pagetables.c:#note_page        | 26         |            |
>> >> | calltrace:mark_rodata_ro                                   | 26         |            |
>> >> | WARNING:at_lib/list_debug.c:#__list_add_valid              | 0          | 17         |
>> >> | calltrace:serio_handle_event                               | 0          | 17         |
>> >> | calltrace:userio_misc_init                                 | 0          | 17         |
>> >> | calltrace:mousedev_init                                    | 0          | 17         |
>> >> | calltrace:evdev_init                                       | 0          | 17         |
>> >> | calltrace:cmos_init                                        | 0          | 17         |
>> >> | calltrace:test_init                                        | 0          | 17         |
>> >> | calltrace:pca_isa_driver_init                              | 0          | 17         |
>> >> | calltrace:vim2m_init                                       | 0          | 17         |
>> >> | calltrace:fm_drv_init                                      | 0          | 17         |
>> >> | calltrace:test_power_init                                  | 0          | 17         |
>> >> | calltrace:raid#_init                                       | 0          | 17         |
>> >> | calltrace:dm_init                                          | 0          | 17         |
>> >> | calltrace:vhci_init                                        | 0          | 17         |
>> >> | calltrace:dcdrbu_init                                      | 0          | 17         |
>> >> | calltrace:dcdbas_init                                      | 0          | 17         |
>> >> | calltrace:uhid_init                                        | 0          | 17         |
>> >> | calltrace:vhost_net_init                                   | 0          | 17         |
>> >> | calltrace:dummy_stm_init                                   | 0          | 17         |
>> >> | calltrace:stm_heartbeat_init                               | 0          | 17         |
>> >> | calltrace:binder_init                                      | 0          | 17         |
>> >> | calltrace:teql_init                                        | 0          | 17         |
>> >> | calltrace:ipip_init                                        | 0          | 17         |
>> >> | calltrace:ipgre_init                                       | 0          | 17         |
>> >> | calltrace:sit_init                                         | 0          | 17         |
>> >> | calltrace:ip6_tunnel_init                                  | 0          | 17         |
>> >> | calltrace:ip6gre_init                                      | 0          | 17         |
>> >> | calltrace:irlan_init                                       | 0          | 17         |
>> >> | calltrace:pm_qos_power_init                                | 0          | 17         |
>> >> | calltrace:ubi_init                                         | 0          | 17         |
>> >> | calltrace:SyS_setsockopt                                   | 0          | 2          |
>> >> | calltrace:SyS_socketcall                                   | 0          | 2          |
>> >> | WARNING:at_include/linux/kref.h:#kobject_get               | 0          | 4          |
>> >> | WARNING:at_kernel/locking/lockdep.c:#__lock_acquire        | 0          | 4          |
>> >> | BUG:kernel_hang_in_test_stage                              | 0          | 4          |
>> >> | calltrace:fw_cfg_sysfs_init                                | 0          | 7          |
>> >> +------------------------------------------------------------+------------+------------+
>> >>
>> >>
>> >>
>> >> [  152.680291] g_acm_ms usbip-vudc.0: failed to start g_acm_ms: -22
>> >> [  152.689209] usbip-vudc: probe of usbip-vudc.0 failed with error -22
>> >> [  152.698509] ------------[ cut here ]------------
>> >> [  152.709786] WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
>> >> [  152.722785] list_del corruption. next->prev should be cc0230d4, but was 6b6b6b6b
>>
>> That's the poison value, so this is a remove-after-remove bug?
>>
>> >> [  152.732828] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc1-00033-g8052ce2 #1
>> >> [  152.742576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
>> >> [  152.754081]  00000000 00200246 c0033e78 c13c456b c0033ea4 c13e72ac c0033e90 c103fd02
>> >> [  152.765720]  0000003c 6b6b6b6b cc0230d4 cc02300c c0033eac c103fd41 00000009 00000000
>> >> [  152.776864]  c0033ea4 c1f7bc14 c0033ec0 c0033ecc c13e72ac c1f7bace 0000003c c1f7bc14
>> >> [  152.788472] Call Trace:
>> >> [  152.791964]  [<c13c456b>] dump_stack+0x75/0xa9
>> >> [  152.797835]  [<c13e72ac>] ? __list_del_entry+0x4d/0x71
>> >> [  152.804221]  [<c103fd02>] __warn+0xad/0xc4
>> >> [  152.809694]  [<c103fd41>] warn_slowpath_fmt+0x28/0x2d
>> >> [  152.816501]  [<c13e72ac>] __list_del_entry+0x4d/0x71
>> >> [  152.822946]  [<c15027a8>] device_pm_remove+0x2b/0x5a
>> >> [  152.829560]  [<c14f6317>] device_del+0x134/0x19a
>> >> [  152.835558]  [<c14f5c38>] ? dev_set_name+0x14/0x16
>> >> [  152.842135]  [<c14f9d7c>] platform_device_del+0x16/0x5d
>> >> [  152.848909]  [<c2207515>] init+0xe5/0x112
>> >> [  152.854149]  [<c2207430>] ? usbip_host_init+0xe5/0xe5
>>
>> What device is this? Looks like it's being removed right at init time??
>>
>> >> [  152.860796]  [<c21cec35>] do_one_initcall+0x7e/0x101
>> >> [  152.867316]  [<c10564b7>] ? parse_args+0x190/0x265
>> >> [  152.873497]  [<c21ced88>] ? kernel_init_freeable+0xd0/0x174
>> >> [  152.880923]  [<c21ceda4>] kernel_init_freeable+0xec/0x174
>> >> [  152.887499]  [<c1be421b>] kernel_init+0x8/0xd0
>> >> [  152.893658]  [<c1bec3ae>] ret_from_kernel_thread+0xe/0x30
>> >> [  152.900759]  [<c1be4213>] ? rest_init+0x111/0x111
>> >> [  152.907334] ---[ end trace 2003739b08d25430 ]---
>> >> [  152.920040] ------------[ cut here ]------------
>>
>> -Kees
>>
>>
>> --
>> Kees Cook
>> Nexus Security
>>
>



-- 
Kees Cook
Nexus Security

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#1478967 — Re: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71

From"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Date2016-09-08 11:30 +0200
SubjectRe: [list] 8052ce2d97: WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
Message-ID<sf3OF-3Y8-3@gated-at.bofh.it>
In reply to#1478520
On Wed, Sep 07, 2016 at 10:25:58AM -0700, Kees Cook wrote:
> On Wed, Sep 7, 2016 at 12:31 AM, Paul E. McKenney
> <paulmck@linux.vnet.ibm.com> wrote:
> > On Tue, Sep 06, 2016 at 11:49:04AM -0400, Kees Cook wrote:
> >> On Sun, Sep 4, 2016 at 5:48 AM, Paul E. McKenney
> >> <paulmck@linux.vnet.ibm.com> wrote:
> >> > On Sun, Sep 04, 2016 at 08:35:40AM +0800, kernel test robot wrote:
> >> >>
> >> >> FYI, we noticed the following commit:
> >> >>
> >> >> https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2016.08.19a
> >> >> commit 8052ce2d9771ab5a818307f3abbaf33bba82a631 ("list: Split list_add() debug checking into separate function")
> >> >>
> >> >> in testcase: boot
> >> >>
> >> >> on test machine: qemu-system-i386 -enable-kvm -m 360M
> >> >>
> >> >> caused below changes:
> >> >
> >> > Hello, Kees,
> >> >
> >> > Looks like your change might have actually found a bug.  ;-)
> >> >
> >> > How would you like to handle this?
> >>
> >> We should fix the bug! :)
> >
> > But of course...
> >
> > The question is whether I am considered to be fully responsible for
> > chasing down any bugs that arise.  It is looking like I am, in which
> > case I must defer this patch to the 4.10 merge window.  Things are a
> > bit crazy now due to prior overcommitments...
> 
> I'm going to double-check the code, but the changes I made shouldn't
> have changed any of the logical checks under CONFIG_DEBUG_LIST... just
> the manifestation of WARN vs BUG. So, since both this and the BPF RCU
> bug have appeared, something has changed... I will go digging...

So maybe the boot failures are a result of the WARN->BUG transition?

							Thanx, Paul

> -Kees
> 
> > Yes, yes, they will be crazy then as well, but this would be higher
> > on the priority list.
> >
> >                                                         Thanx, Paul
> >
> >> >> +------------------------------------------------------------+------------+------------+
> >> >> |                                                            | 0a33d912a3 | 8052ce2d97 |
> >> >> +------------------------------------------------------------+------------+------------+
> >> >> | boot_successes                                             | 0          | 0          |
> >> >> | boot_failures                                              | 211        | 18         |
> >> >> | WARNING:at_lib/list_debug.c:#__list_del_entry              | 211        | 18         |
> >> >> | calltrace:init                                             | 209        | 18         |
> >> >> | WARNING:at_lib/list_debug.c:#__list_add                    | 209        |            |
> >> >> | calltrace:i8042_init                                       | 209        | 17         |
> >> >> | calltrace:SyS_reboot                                       | 192        | 4          |
> >> >> | EIP_is_at__mutex_unlock_slowpath                           | 29         |            |
> >> >> | Kernel_panic-not_syncing:softlockup:hung_tasks             | 138        |            |
> >> >> | BUG:workqueue_lockup-pool_cpus=#flags=#nice=#stuck_for#s   | 56         |            |
> >> >> | EIP_is_at_lock_release                                     | 7          |            |
> >> >> | EIP_is_at_lock_acquire                                     | 28         |            |
> >> >> | EIP_is_at_raw_spin_unlock_irq                              | 30         |            |
> >> >> | EIP_is_at_mutex_lock_nested                                | 21         |            |
> >> >> | EIP_is_at_lock_is_held                                     | 10         |            |
> >> >> | EIP_is_at_device_shutdown                                  | 3          |            |
> >> >> | EIP_is_at___might_sleep                                    | 5          |            |
> >> >> | EIP_is_at__list_del_entry                                  | 4          | 1          |
> >> >> | EIP_is_at_get_device                                       | 1          |            |
> >> >> | BUG:unable_to_handle_kernel                                | 7          | 5          |
> >> >> | Oops                                                       | 7          | 5          |
> >> >> | calltrace:SyS_ipc                                          | 4          | 4          |
> >> >> | Kernel_panic-not_syncing:Fatal_exception                   | 7          | 5          |
> >> >> | EIP_is_at_pm_runtime_barrier                               | 1          |            |
> >> >> | EIP_is_at_lock_acquired                                    | 1          |            |
> >> >> | EIP_is_at__might_sleep                                     | 1          |            |
> >> >> | BUG:workqueue_lockup-pool_cpus=#-#flags=#nice=#stuck_for#s | 1          |            |
> >> >> | WARNING:at_arch/x86/mm/dump_pagetables.c:#note_page        | 26         |            |
> >> >> | calltrace:mark_rodata_ro                                   | 26         |            |
> >> >> | WARNING:at_lib/list_debug.c:#__list_add_valid              | 0          | 17         |
> >> >> | calltrace:serio_handle_event                               | 0          | 17         |
> >> >> | calltrace:userio_misc_init                                 | 0          | 17         |
> >> >> | calltrace:mousedev_init                                    | 0          | 17         |
> >> >> | calltrace:evdev_init                                       | 0          | 17         |
> >> >> | calltrace:cmos_init                                        | 0          | 17         |
> >> >> | calltrace:test_init                                        | 0          | 17         |
> >> >> | calltrace:pca_isa_driver_init                              | 0          | 17         |
> >> >> | calltrace:vim2m_init                                       | 0          | 17         |
> >> >> | calltrace:fm_drv_init                                      | 0          | 17         |
> >> >> | calltrace:test_power_init                                  | 0          | 17         |
> >> >> | calltrace:raid#_init                                       | 0          | 17         |
> >> >> | calltrace:dm_init                                          | 0          | 17         |
> >> >> | calltrace:vhci_init                                        | 0          | 17         |
> >> >> | calltrace:dcdrbu_init                                      | 0          | 17         |
> >> >> | calltrace:dcdbas_init                                      | 0          | 17         |
> >> >> | calltrace:uhid_init                                        | 0          | 17         |
> >> >> | calltrace:vhost_net_init                                   | 0          | 17         |
> >> >> | calltrace:dummy_stm_init                                   | 0          | 17         |
> >> >> | calltrace:stm_heartbeat_init                               | 0          | 17         |
> >> >> | calltrace:binder_init                                      | 0          | 17         |
> >> >> | calltrace:teql_init                                        | 0          | 17         |
> >> >> | calltrace:ipip_init                                        | 0          | 17         |
> >> >> | calltrace:ipgre_init                                       | 0          | 17         |
> >> >> | calltrace:sit_init                                         | 0          | 17         |
> >> >> | calltrace:ip6_tunnel_init                                  | 0          | 17         |
> >> >> | calltrace:ip6gre_init                                      | 0          | 17         |
> >> >> | calltrace:irlan_init                                       | 0          | 17         |
> >> >> | calltrace:pm_qos_power_init                                | 0          | 17         |
> >> >> | calltrace:ubi_init                                         | 0          | 17         |
> >> >> | calltrace:SyS_setsockopt                                   | 0          | 2          |
> >> >> | calltrace:SyS_socketcall                                   | 0          | 2          |
> >> >> | WARNING:at_include/linux/kref.h:#kobject_get               | 0          | 4          |
> >> >> | WARNING:at_kernel/locking/lockdep.c:#__lock_acquire        | 0          | 4          |
> >> >> | BUG:kernel_hang_in_test_stage                              | 0          | 4          |
> >> >> | calltrace:fw_cfg_sysfs_init                                | 0          | 7          |
> >> >> +------------------------------------------------------------+------------+------------+
> >> >>
> >> >>
> >> >>
> >> >> [  152.680291] g_acm_ms usbip-vudc.0: failed to start g_acm_ms: -22
> >> >> [  152.689209] usbip-vudc: probe of usbip-vudc.0 failed with error -22
> >> >> [  152.698509] ------------[ cut here ]------------
> >> >> [  152.709786] WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
> >> >> [  152.722785] list_del corruption. next->prev should be cc0230d4, but was 6b6b6b6b
> >>
> >> That's the poison value, so this is a remove-after-remove bug?
> >>
> >> >> [  152.732828] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc1-00033-g8052ce2 #1
> >> >> [  152.742576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
> >> >> [  152.754081]  00000000 00200246 c0033e78 c13c456b c0033ea4 c13e72ac c0033e90 c103fd02
> >> >> [  152.765720]  0000003c 6b6b6b6b cc0230d4 cc02300c c0033eac c103fd41 00000009 00000000
> >> >> [  152.776864]  c0033ea4 c1f7bc14 c0033ec0 c0033ecc c13e72ac c1f7bace 0000003c c1f7bc14
> >> >> [  152.788472] Call Trace:
> >> >> [  152.791964]  [<c13c456b>] dump_stack+0x75/0xa9
> >> >> [  152.797835]  [<c13e72ac>] ? __list_del_entry+0x4d/0x71
> >> >> [  152.804221]  [<c103fd02>] __warn+0xad/0xc4
> >> >> [  152.809694]  [<c103fd41>] warn_slowpath_fmt+0x28/0x2d
> >> >> [  152.816501]  [<c13e72ac>] __list_del_entry+0x4d/0x71
> >> >> [  152.822946]  [<c15027a8>] device_pm_remove+0x2b/0x5a
> >> >> [  152.829560]  [<c14f6317>] device_del+0x134/0x19a
> >> >> [  152.835558]  [<c14f5c38>] ? dev_set_name+0x14/0x16
> >> >> [  152.842135]  [<c14f9d7c>] platform_device_del+0x16/0x5d
> >> >> [  152.848909]  [<c2207515>] init+0xe5/0x112
> >> >> [  152.854149]  [<c2207430>] ? usbip_host_init+0xe5/0xe5
> >>
> >> What device is this? Looks like it's being removed right at init time??
> >>
> >> >> [  152.860796]  [<c21cec35>] do_one_initcall+0x7e/0x101
> >> >> [  152.867316]  [<c10564b7>] ? parse_args+0x190/0x265
> >> >> [  152.873497]  [<c21ced88>] ? kernel_init_freeable+0xd0/0x174
> >> >> [  152.880923]  [<c21ceda4>] kernel_init_freeable+0xec/0x174
> >> >> [  152.887499]  [<c1be421b>] kernel_init+0x8/0xd0
> >> >> [  152.893658]  [<c1bec3ae>] ret_from_kernel_thread+0xe/0x30
> >> >> [  152.900759]  [<c1be4213>] ? rest_init+0x111/0x111
> >> >> [  152.907334] ---[ end trace 2003739b08d25430 ]---
> >> >> [  152.920040] ------------[ cut here ]------------
> >>
> >> -Kees
> >>
> >>
> >> --
> >> Kees Cook
> >> Nexus Security
> >>
> >
> 
> 
> 
> -- 
> Kees Cook
> Nexus Security
> 

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#1479351

FromKees Cook <keescook@chromium.org>
Date2016-09-08 18:00 +0200
Message-ID<sf9U6-7DZ-13@gated-at.bofh.it>
In reply to#1478967
On Thu, Sep 8, 2016 at 2:27 AM, Paul E. McKenney
<paulmck@linux.vnet.ibm.com> wrote:
> On Wed, Sep 07, 2016 at 10:25:58AM -0700, Kees Cook wrote:
>> On Wed, Sep 7, 2016 at 12:31 AM, Paul E. McKenney
>> <paulmck@linux.vnet.ibm.com> wrote:
>> > On Tue, Sep 06, 2016 at 11:49:04AM -0400, Kees Cook wrote:
>> >> On Sun, Sep 4, 2016 at 5:48 AM, Paul E. McKenney
>> >> <paulmck@linux.vnet.ibm.com> wrote:
>> >> > On Sun, Sep 04, 2016 at 08:35:40AM +0800, kernel test robot wrote:
>> >> >>
>> >> >> FYI, we noticed the following commit:
>> >> >>
>> >> >> https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2016.08.19a
>> >> >> commit 8052ce2d9771ab5a818307f3abbaf33bba82a631 ("list: Split list_add() debug checking into separate function")
>> >> >>
>> >> >> in testcase: boot
>> >> >>
>> >> >> on test machine: qemu-system-i386 -enable-kvm -m 360M
>> >> >>
>> >> >> caused below changes:
>> >> >
>> >> > Hello, Kees,
>> >> >
>> >> > Looks like your change might have actually found a bug.  ;-)
>> >> >
>> >> > How would you like to handle this?
>> >>
>> >> We should fix the bug! :)
>> >
>> > But of course...
>> >
>> > The question is whether I am considered to be fully responsible for
>> > chasing down any bugs that arise.  It is looking like I am, in which
>> > case I must defer this patch to the 4.10 merge window.  Things are a
>> > bit crazy now due to prior overcommitments...
>>
>> I'm going to double-check the code, but the changes I made shouldn't
>> have changed any of the logical checks under CONFIG_DEBUG_LIST... just
>> the manifestation of WARN vs BUG. So, since both this and the BPF RCU
>> bug have appeared, something has changed... I will go digging...
>
> So maybe the boot failures are a result of the WARN->BUG transition?
>
>> >> >> [  152.698509] ------------[ cut here ]------------
>> >> >> [  152.709786] WARNING: CPU: 0 PID: 1 at lib/list_debug.c:60 __list_del_entry+0x4d/0x71
>> >> >> [  152.722785] list_del corruption. next->prev should be cc0230d4, but was 6b6b6b6b
>> >>
>> >> That's the poison value, so this is a remove-after-remove bug?

Unfortunately, the 0-day backtrace shows WARN :(

-Kees

-- 
Kees Cook
Nexus Security

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