Sorry, I am out till Tuesday and won't be able to take a look at this
problem.

sent from phone

On Aug 12, 2016 11:57 AM, "Fengguang Wu" <fengguang.wu@intel.com> wrote:

> On Fri, Aug 12, 2016 at 03:48:08PM +0800, Fengguang Wu wrote:
>
>> On Thu, Aug 11, 2016 at 01:35:03PM -0700, Andrew Morton wrote:
>>
>>> On Thu, 11 Aug 2016 12:52:27 +0800 kernel test robot <
>>> fengguang.wu@intel.com> wrote:
>>>
>>> Greetings,
>>>>
>>>> 0day kernel testing robot got the below dmesg and the first bad commit
>>>> is
>>>>
>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>>>> master
>>>>
>>>> commit 80a9201a5965f4715d5c09790862e0df84ce0614
>>>> Author:     Alexander Potapenko <glider@google.com>
>>>> AuthorDate: Thu Jul 28 15:49:07 2016 -0700
>>>> Commit:     Linus Torvalds <torvalds@linux-foundation.org>
>>>> CommitDate: Thu Jul 28 16:07:41 2016 -0700
>>>>
>>>>     mm, kasan: switch SLUB to stackdepot, enable memory quarantine for
>>>> SLUB
>>>>
>>>>     For KASAN builds:
>>>>      - switch SLUB allocator to using stackdepot instead of storing the
>>>>        allocation/deallocation stacks in the objects;
>>>>      - change the freelist hook so that parts of the freelist can be put
>>>>        into the quarantine.
>>>>
>>>> ...
>>>>
>>>> [   64.298576] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s!
>>>> [swapper/0:1]
>>>> [   64.300827] irq event stamp: 5606950
>>>> [   64.301377] hardirqs last  enabled at (5606949):
>>>> [<ffffffff98a4ef09>] T.2097+0x9a/0xbe
>>>> [   64.302586] hardirqs last disabled at (5606950):
>>>> [<ffffffff997347a9>] apic_timer_interrupt+0x89/0xa0
>>>> [   64.303991] softirqs last  enabled at (5605564):
>>>> [<ffffffff99735abe>] __do_softirq+0x23e/0x2bb
>>>> [   64.305308] softirqs last disabled at (5605557):
>>>> [<ffffffff988ee34f>] irq_exit+0x73/0x108
>>>> [   64.306598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
>>>> 4.7.0-05999-g80a9201 #1
>>>> [   64.307678] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
>>>> BIOS Debian-1.8.2-1 04/01/2014
>>>> [   64.326233] task: ffff88000ea19ec0 task.stack: ffff88000ea20000
>>>> [   64.327137] RIP: 0010:[<ffffffff9890f590>]  [<ffffffff9890f590>]
>>>> __kernel_text_address+0xb/0xa1
>>>> [   64.328504] RSP: 0000:ffff88000ea27348  EFLAGS: 00000207
>>>> [   64.329320] RAX: 0000000000000001 RBX: ffff88000ea275c0 RCX:
>>>> 0000000000000001
>>>> [   64.330426] RDX: ffff88000ea27ff8 RSI: 024080c099733d8f RDI:
>>>> 024080c099733d8f
>>>> [   64.331496] RBP: ffff88000ea27348 R08: ffff88000ea27678 R09:
>>>> 0000000000000000
>>>> [   64.332567] R10: 0000000000021298 R11: ffffffff990f235c R12:
>>>> ffff88000ea276c8
>>>> [   64.333635] R13: ffffffff99805e20 R14: ffff88000ea19ec0 R15:
>>>> 0000000000000000
>>>> [   64.334706] FS:  0000000000000000(0000) GS:ffff88000ee00000(0000)
>>>> knlGS:0000000000000000
>>>> [   64.335916] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>> [   64.336782] CR2: 0000000000000000 CR3: 000000000aa0a000 CR4:
>>>> 00000000000406b0
>>>> [   64.337846] Stack:
>>>> [   64.338206]  ffff88000ea273a8 ffffffff9881f3dd 024080c099733d8f
>>>> ffffffffffff8000
>>>> [   64.339410]  ffff88000ea27678 ffff88000ea276c8 000000020e81a4d8
>>>> ffff88000ea273f8
>>>> [   64.340602]  ffffffff99805e20 ffff88000ea19ec0 ffff88000ea27438
>>>> ffff88000ee07fc0
>>>> [   64.348993] Call Trace:
>>>> [   64.349380]  [<ffffffff9881f3dd>] print_context_stack+0x68/0x13e
>>>> [   64.350295]  [<ffffffff9881e4af>] dump_trace+0x3ab/0x3d6
>>>> [   64.351102]  [<ffffffff9882f6e4>] save_stack_trace+0x31/0x5c
>>>> [   64.351964]  [<ffffffff98a521db>] kasan_kmalloc+0x126/0x1f6
>>>> [   64.365727]  [<ffffffff9882f6e4>] ? save_stack_trace+0x31/0x5c
>>>> [   64.366675]  [<ffffffff98a521db>] ? kasan_kmalloc+0x126/0x1f6
>>>> [   64.367560]  [<ffffffff9904a8eb>] ? acpi_ut_create_generic_state+0
>>>> x43/0x5c
>>>>
>>>>
>>> At a guess I'd say that
>>> arch/x86/kernel/dumpstack.c:print_context_stack() failed to terminate,
>>> or took a super long time.  Is that a thing that is known to be possible?
>>>
>>
>> Andrew, note that this kernel is compiled with gcc-4.4.
>>
>> This commit caused the below problems, too, with gcc-4.4. However they
>> no longer show up in mainline HEAD, so not reported before.
>>
>
> The gcc-6 results are roughly the same:
>
>
>          parent       first-bad     mainline
> +-----------------------------------------------------------
> -----------------------+------------+------------+------------+
> |
>         | c146a2b98e | 80a9201a59 | 4b9eaf33d8 |
> +-----------------------------------------------------------
> -----------------------+------------+------------+------------+
> | boot_successes
>          | 110        | 30         | 102        |
> | boot_failures
>         | 2          | 80         | 10         |
> | IP-Config:Auto-configuration_of_network_failed
>          | 2          | 1          |            |
> | Mem-Info
>          | 0          | 4          | 7          |
> | BUG_anon_vma_chain(Not_tainted):Poison_overwritten
>          | 0          | 17         |            |
> | INFO:#-#.First_byte#instead_of
>          | 0          | 53         |            |
> | INFO:Allocated_in_anon_vma_clone_age=#cpu=#pid=
>           | 0          | 15         |            |
> | INFO:Freed_in_qlist_free_all_age=#cpu=#pid=
>           | 0          | 52         |            |
> | INFO:Slab#objects=#used=#fp=0x(null)flags=
>          | 0          | 51         |            |
> | INFO:Object#@offset=#fp=
>          | 0          | 45         |            |
> | backtrace:SyS_clone
>         | 0          | 50         |            |
> | BUG_kmalloc-#(Not_tainted):Poison_overwritten
>           | 0          | 11         |            |
> | INFO:Allocated_in_kernfs_fop_open_age=#cpu=#pid=
>          | 0          | 3          |            |
> | backtrace:SyS_open
>          | 0          | 9          |            |
> | invoked_oom-killer:gfp_mask=0x
>          | 0          | 1          | 3          |
> | Out_of_memory:Kill_process
>          | 0          | 1          | 3          |
> | backtrace:SyS_mlockall
>          | 0          | 2          | 5          |
> | INFO:Allocated_in_anon_vma_prepare_age=#cpu=#pid=
>           | 0          | 7          |            |
> | backtrace:do_execve
>         | 0          | 29         |            |
> | backtrace:SyS_execve
>          | 0          | 30         |            |
> | BUG_vm_area_struct(Not_tainted):Poison_overwritten
>          | 0          | 11         |            |
> | INFO:Allocated_in_copy_process_age=#cpu=#pid=
>           | 0          | 10         |            |
> | backtrace:mmap_region
>         | 0          | 6          |            |
> | backtrace:SyS_mmap_pgoff
>          | 0          | 5          |            |
> | backtrace:SyS_mmap
>          | 0          | 5          |            |
> | INFO:Allocated_in_mmap_region_age=#cpu=#pid=
>          | 0          | 5          |            |
> | backtrace:mprotect_fixup
>          | 0          | 7          |            |
> | backtrace:SyS_mprotect
>          | 0          | 7          |            |
> | BUG_skbuff_head_cache(Not_tainted):Poison_overwritten
>           | 0          | 2          |            |
> | INFO:Allocated_in__alloc_skb_age=#cpu=#pid=
>           | 0          | 5          |            |
> | backtrace:vfs_write
>         | 0          | 5          |            |
> | backtrace:SyS_write
>         | 0          | 5          |            |
> | BUG_names_cache(Not_tainted):Poison_overwritten
>           | 0          | 6          |            |
> | INFO:Allocated_in_getname_flags_age=#cpu=#pid=
>          | 0          | 8          |            |
> | INFO:Allocated_in_do_execveat_common_age=#cpu=#pid=
>           | 0          | 4          |            |
> | BUG_files_cache(Tainted:G_B):Poison_overwritten
>           | 0          | 1          |            |
> | Oops
>          | 0          | 10         |            |
> | Kernel_panic-not_syncing:Fatal_exception
>          | 0          | 28         | 1          |
> | BUG:unable_to_handle_kernel
>         | 0          | 10         |            |
> | RIP:vt_console_print
>          | 0          | 10         |            |
> | BUG:KASAN:use-after-free_in_vma_interval_tree_compute_subtree_last_at_addr
>      | 0          | 5          |            |
> | BUG:KASAN:use-after-free_in_vma_compute_subtree_gap_at_addr
>           | 0          | 2          |            |
> | backtrace:load_script
>         | 0          | 11         |            |
> | backtrace:_do_fork
>          | 0          | 25         |            |
> | BUG:KASAN:use-after-free_in_put_pid_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_handle_mm_fault_at_addr
>           | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_native_set_pte_at_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_unmap_page_range_at_addr
>          | 0          | 3          |            |
> | BUG:Bad_page_map_in_process
>         | 0          | 2          |            |
> | backtrace:smpboot_thread_fn
>         | 0          | 1          |            |
> | backtrace:ret_from_fork
>         | 0          | 2          | 1          |
> | backtrace:do_group_exit
>         | 0          | 13         |            |
> | backtrace:SyS_exit_group
>          | 0          | 13         |            |
> | INFO:Object#@offset=#fp=0x(null)
>          | 0          | 16         |            |
> | general_protection_fault:#[##]PREEMPT_KASAN
>           | 0          | 18         | 1          |
> | RIP:remove_full
>         | 0          | 3          |            |
> | backtrace:SyS_newstat
>         | 0          | 3          |            |
> | BUG_anon_vma_chain(Tainted:G_B):Poison_overwritten
>          | 0          | 16         |            |
> | backtrace:getname
>         | 0          | 1          |            |
> | backtrace:kernfs_fop_read
>         | 0          | 5          |            |
> | backtrace:vfs_read
>          | 0          | 5          |            |
> | backtrace:SyS_read
>          | 0          | 5          |            |
> | BUG:KASAN:use-after-free_in__rb_insert_augmented_at_addr
>          | 0          | 8          |            |
> | BUG:KASAN:use-after-free_in_find_vma_at_addr
>          | 0          | 4          |            |
> | BUG:KASAN:use-after-free_in_vmacache_update_at_addr
>           | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_vma_interval_tree_remove_at_addr
>          | 0          | 3          |            |
> | BUG:KASAN:use-after-free_in__do_page_fault_at_addr
>          | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_arch_vma_access_permitted_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in__rb_erase_color_at_addr
>           | 0          | 6          |            |
> | BUG:KASAN:use-after-free_in_wp_page_copy_at_addr
>          | 0          | 1          |            |
> | BUG_vm_area_struct(Tainted:G_B):Poison_overwritten
>          | 0          | 7          |            |
> | BUG:KASAN:use-after-free_in_get_page_from_freelist_at_addr
>          | 0          | 1          |            |
> | BUG_dentry(Tainted:G_B):Poison_overwritten
>          | 0          | 1          |            |
> | INFO:Allocated_in__d_alloc_age=#cpu=#pid=
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_unlink_anon_vmas_at_addr
>          | 0          | 15         |            |
> | RIP:unlink_anon_vmas
>          | 0          | 12         |            |
> | backtrace:SyS_readlink
>          | 0          | 3          |            |
> | INFO:Allocated_in_kzalloc_age=#cpu=#pid=
>          | 0          | 6          |            |
> | BUG_kmalloc-#(Tainted:G_B):Poison_overwritten
>           | 0          | 10         |            |
> | INFO:Allocated_in_load_elf_phdrs_age=#cpu=#pid=
>           | 0          | 3          |            |
> | INFO:Allocated_in_do_brk_age=#cpu=#pid=
>           | 0          | 1          |            |
> | INFO:Allocated_in_anon_vma_fork_age=#cpu=#pid=
>          | 0          | 9          |            |
> | BUG:KASAN:use-after-free_in__anon_vma_interval_tree_compute_subtree_last_at_addr
> | 0          | 6          |            |
> | BUG:KASAN:use-after-free_in__anon_vma_interval_tree_augment_rotate_at_addr
>      | 0          | 4          |            |
> | BUG:KASAN:use-after-free_in__rb_rotate_set_parents_at_addr
>          | 0          | 7          |            |
> | BUG:KASAN:use-after-free_in_anon_vma_interval_tree_remove_at_addr
>           | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in__anon_vma_interval_tree_augment_propagate_at_addr
>   | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_anon_vma_interval_tree_insert_at_addr
>           | 0          | 4          |            |
> | INFO:Slab#objects=#used=#fp=#flags=
>           | 0          | 3          |            |
> | BUG_names_cache(Tainted:G_B):Poison_overwritten
>           | 0          | 4          |            |
> | backtrace:SyS_mount
>         | 0          | 1          |            |
> | backtrace:SyS_symlink
>         | 0          | 3          |            |
> | BUG_skbuff_head_cache(Tainted:G_B):Poison_overwritten
>           | 0          | 2          |            |
> | backtrace:SyS_sendto
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_vma_interval_tree_augment_rotate_at_addr
>          | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_vma_last_pgoff_at_addr
>          | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_vma_interval_tree_augment_propagate_at_addr
>         | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_vma_interval_tree_insert_at_addr
>          | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_unmap_vmas_at_addr
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_print_bad_pte_at_addr
>           | 0          | 1          |            |
> | backtrace:vm_mmap_pgoff
>         | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_copy_process_at_addr
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_anon_vma_fork_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_copy_page_range_at_addr
>           | 0          | 1          |            |
> | backtrace:___slab_alloc
>         | 0          | 3          |            |
> | RIP:__wake_up_common
>          | 0          | 1          | 1          |
> | backtrace:fd_timer_workfn
>         | 0          | 1          | 1          |
> | INFO:Allocated_in__install_special_mapping_age=#cpu=#pid=
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_locks_remove_posix_at_addr
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in___sys_sendmsg_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_sock_sendmsg_nosec_at_addr
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_netlink_sendmsg_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in__sys_sendmsg_at_addr
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_sock_poll_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_datagram_poll_at_addr
>           | 0          | 1          |            |
> | backtrace:SyS_pipe
>          | 0          | 1          |            |
> | backtrace:__close_fd
>          | 0          | 1          |            |
> | backtrace:SyS_close
>         | 0          | 1          |            |
> | backtrace:SYSC_socket
>         | 0          | 1          |            |
> | backtrace:SyS_socket
>          | 0          | 2          |            |
> | backtrace:SyS_sendmsg
>         | 0          | 3          |            |
> | backtrace:__sys_sendmsg
>         | 0          | 1          |            |
> | backtrace:SyS_ppoll
>         | 0          | 1          |            |
> | BUG_files_cache(Not_tainted):Poison_overwritten
>           | 0          | 1          |            |
> | INFO:Allocated_in_dup_fd_age=#cpu=#pid=
>           | 0          | 1          |            |
> | INFO:Allocated_in_uevent_show_age=#cpu=#pid=
>          | 0          | 1          |            |
> | backtrace:SyS_munmap
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_anon_vma_clone_at_addr
>          | 0          | 2          |            |
> | RIP:anon_vma_clone
>          | 0          | 2          |            |
> | INFO:Allocated_in_getname_kernel_age=#cpu=#pid=
>           | 0          | 2          |            |
> | INFO:Allocated_in__split_vma_age=#cpu=#pid=
>           | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_rcu_process_callbacks_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_unlink_file_vma_at_addr
>           | 0          | 2          |            |
> | BUG:KASAN:use-after-free_in_remove_vma_at_addr
>          | 0          | 2          |            |
> | backtrace:SYSC_newstat
>          | 0          | 1          |            |
> | BUG_fs_cache(Tainted:G_B):Poison_overwritten
>          | 0          | 1          |            |
> | INFO:Allocated_in_copy_fs_struct_age=#cpu=#pid=
>           | 0          | 1          |            |
> | backtrace:handle_mm_fault
>         | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_unmapped_area_topdown_at_addr
>           | 0          | 1          |            |
> | INFO:Allocated_in__list_lru_init_age=#cpu=#pid=
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in__vma_link_rb_at_addr
>          | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_vma_gap_callbacks_propagate_at_addr
>           | 0          | 1          |            |
> | backtrace:SyS_mknod
>         | 0          | 1          |            |
> | INFO:Allocated_in_kobject_uevent_env_age=#cpu=#pid=
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_free_pgtables_at_addr
>           | 0          | 1          |            |
> | BUG:KASAN:use-after-free_in_exit_mmap_at_addr
>           | 0          | 1          |            |
> | BUG:kernel_test_oversize
>          | 0          | 0          | 2          |
> +-----------------------------------------------------------
> -----------------------+------------+------------+------------+
>
>
> Here are the detailed Oops listing on this commit, with the trinity OOMs
> removed.
>
> dmesg-quantal-ivb41-10:20160812160230:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  101.754306] init: Failed to create pty - disabling logging for job
> [  101.860052] init: Temporary process spawn error: No such file or
> directory
> [  101.939827] ==============================
> ===============================================
> [  101.943713] BUG anon_vma_chain (Not tainted): Poison overwritten
> [  101.946151] ------------------------------
> -----------------------------------------------
> [  101.946151] [  101.956210] Disabling lock debugging due to kernel taint
> [  101.961535] INFO: 0xffff88000922e9d5-0xffff88000922e9d7. First byte
> 0x1 instead of 0x6b
> [  101.968051] INFO: Allocated in anon_vma_clone+0x9f/0x375 age=536 cpu=0
> pid=253
> [  102.012093] INFO: Freed in qlist_free_all+0x33/0xac age=59 cpu=0 pid=255
> [  102.073932] INFO: Slab 0xffffea0000248b80 objects=19 used=19 fp=0x
>     (null) flags=0x4000000000004080
> [  102.084787] INFO: Object 0xffff88000922e9c8 @offset=2504
> fp=0xffff88000922f388
> [  102.084787] [  102.095451] Redzone ffff88000922e9c0: bb bb bb bb bb bb
> bb bb                          ........
> [  102.103305] Object ffff88000922e9c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 01 40 82  kkkkkkkkkkkkk.@.
> [  102.111187] Object ffff88000922e9d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  102.119169] Object ffff88000922e9e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  102.127071] Object ffff88000922e9f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
> [  102.138649] Redzone ffff88000922ea08: bb bb bb bb bb bb bb bb
>                 ........
> [  102.142155] Padding ffff88000922eb54: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a
> 5a              ZZZZZZZZZZZZ
> [  102.145703] CPU: 0 PID: 255 Comm: udevd Tainted: G    B
>  4.7.0-05999-g80a9201 #1
> [  102.149473] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> Debian-1.8.2-1 04/01/2014
> [  102.154920]  0000000000000000 ffff88000a2a79d8 ffffffff81c91ab5
> ffff88000a2a7a08
> [  102.158925]  ffffffff81330f07 ffff88000922e9d5 000000000000006b
> ffff8800110131c0
> [  102.162965]  ffff88000922e9d7 ffff88000a2a7a58 ffffffff81330fac
> ffffffff83592f26
> [  102.166534] Call Trace:
> [  102.167926]  [<ffffffff81c91ab5>] dump_stack+0x19/0x1b
> [  102.169917]  [<ffffffff81330f07>] print_trailer+0x15b/0x164
> [  102.172282]  [<ffffffff81330fac>] check_bytes_and_report+0x9c/0xef
> [  102.174549]  [<ffffffff8133194d>] check_object+0x12f/0x1fb
> [  102.176815]  [<ffffffff81315ac6>] ? anon_vma_clone+0x9f/0x375
> [  102.180023]  [<ffffffff81331f00>] alloc_debug_processing+0x7e/0x10d
> [  102.182520]  [<ffffffff8133211b>] ___slab_alloc+0x18c/0x31e
> [  102.184919]  [<ffffffff81315ac6>] ? anon_vma_clone+0x9f/0x375
> [  102.187331]  [<ffffffff81334818>] ? kasan_unpoison_shadow+0x14/0x35
> [  102.189613]  [<ffffffff811f1079>] ? ___might_sleep+0xa4/0x321
> [  102.191936]  [<ffffffff81315ac6>] ? anon_vma_clone+0x9f/0x375
> [  102.194468]  [<ffffffff813322c3>] __slab_alloc+0x16/0x2a
> [  102.197302]  [<ffffffff813322c3>] ? __slab_alloc+0x16/0x2a
> [  102.200729]  [<ffffffff81332b53>] kmem_cache_alloc+0x50/0xb6
> [  102.203125]  [<ffffffff81315ac6>] anon_vma_clone+0x9f/0x375
> [  102.205249]  [<ffffffff81315e34>] anon_vma_fork+0x98/0x3f9
> [  102.207331]  [<ffffffff811a9c9a>] copy_process+0x246d/0x424c
> [  102.209633]  [<ffffffff811a782d>] ? __cleanup_sighand+0x23/0x23
> [  102.212180]  [<ffffffff81380da8>] ? put_unused_fd+0x6f/0x6f
> [  102.214374]  [<ffffffff811f1079>] ? ___might_sleep+0xa4/0x321
> [  102.216708]  [<ffffffff811abe13>] _do_fork+0x159/0x3d9
> [  102.219151]  [<ffffffff811abcba>] ? fork_idle+0x1ed/0x1ed
> [  102.221418]  [<ffffffff813596a7>] ? __do_pipe_flags+0x1aa/0x1aa
> [  102.223830]  [<ffffffff8111d106>] ? __do_page_fault+0x519/0x624
> [  102.225997]  [<ffffffff82c80800>] ? ptregs_sys_rt_sigreturn+0x10/0x10
> [  102.228515]  [<ffffffff811ac105>] SyS_clone+0x14/0x16
> [  102.230565]  [<ffffffff81002ab8>] do_syscall_64+0x1be/0x1fa
> [  102.232791]  [<ffffffff8111d254>] ? do_page_fault+0x22/0x27
> [  102.235308]  [<ffffffff82c80722>] entry_SYSCALL64_slow_path+0x25/0x25
> [  102.237796] FIX anon_vma_chain: Restoring 0xffff88000922e9d5-0xffff88000
> 922e9d7=0x6b
>
> dmesg-quantal-ivb41-129:20160812160254:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  111.625693] power_supply test_usb: POWER_SUPPLY_NAME=test_usb
> [  111.625717] power_supply test_usb: prop ONLINE=1
> [  113.494934] ==============================
> ===============================================
> [  113.494939] BUG kmalloc-64 (Not tainted): Poison overwritten
> [  113.494940] ------------------------------
> -----------------------------------------------
> [  113.494940] [  113.494941] Disabling lock debugging due to kernel taint
> [  113.494944] INFO: 0xffff88000a70b535-0xffff88000a70b537. First byte
> 0x1 instead of 0x6b
> [  113.494953] INFO: Allocated in kernfs_fop_open+0x6fb/0x840 age=153
> cpu=0 pid=246
> [  113.494993] INFO: Freed in qlist_free_all+0x33/0xac age=86 cpu=0 pid=238
> [  113.495036] INFO: Slab 0xffffea000029c280 objects=19 used=19 fp=0x
>     (null) flags=0x4000000000004080
> [  113.495039] INFO: Object 0xffff88000a70b528 @offset=5416
> fp=0xffff88000a70a828
> [  113.495039] [  113.495043] Redzone ffff88000a70b520: bb bb bb bb bb bb
> bb bb                          ........
> [  113.495046] Object ffff88000a70b528: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 01 a0 c9  kkkkkkkkkkkkk...
> [  113.495049] Object ffff88000a70b538: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  113.495052] Object ffff88000a70b548: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  113.495054] Object ffff88000a70b558: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
> [  113.495057] Redzone ffff88000a70b568: bb bb bb bb bb bb bb bb
>                 ........
> [  113.495060] Padding ffff88000a70b6b4: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a
> 5a              ZZZZZZZZZZZZ
> [  113.495064] CPU: 0 PID: 238 Comm: udevd Tainted: G    B
>  4.7.0-05999-g80a9201 #1
> [  113.495066] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> Debian-1.8.2-1 04/01/2014
> [  113.495071]  0000000000000000 ffff88000adc77d8 ffffffff81c91ab5
> ffff88000adc7808
> [  113.495075]  ffffffff81330f07 ffff88000a70b535 000000000000006b
> ffff8800110036c0
> [  113.495079]  ffff88000a70b537 ffff88000adc7858 ffffffff81330fac
> ffffffff83592f26
> [  113.495079] Call Trace:
> [  113.495084]  [<ffffffff81c91ab5>] dump_stack+0x19/0x1b
> [  113.495088]  [<ffffffff81330f07>] print_trailer+0x15b/0x164
> [  113.495091]  [<ffffffff81330fac>] check_bytes_and_report+0x9c/0xef
> [  113.495094]  [<ffffffff8133194d>] check_object+0x12f/0x1fb
> [  113.495098]  [<ffffffff81425fc3>] ? kernfs_fop_open+0x6fb/0x840
> [  113.495101]  [<ffffffff81331f00>] alloc_debug_processing+0x7e/0x10d
> [  113.495104]  [<ffffffff8133211b>] ___slab_alloc+0x18c/0x31e
> [  113.495108]  [<ffffffff81334595>] ? kasan_poison_shadow+0x2f/0x31
> [  113.495111]  [<ffffffff81425fc3>] ? kernfs_fop_open+0x6fb/0x840
> [  113.495116]  [<ffffffff811f1079>] ? ___might_sleep+0xa4/0x321
> [  113.495119]  [<ffffffff81425fc3>] ? kernfs_fop_open+0x6fb/0x840
> [  113.495123]  [<ffffffff813322c3>] __slab_alloc+0x16/0x2a
> [  113.495126]  [<ffffffff813322c3>] ? __slab_alloc+0x16/0x2a
> [  113.495129]  [<ffffffff81332b53>] kmem_cache_alloc+0x50/0xb6
> [  113.495133]  [<ffffffff81425fc3>] kernfs_fop_open+0x6fb/0x840
> [  113.495136]  [<ffffffff81342aed>] do_dentry_open+0x361/0x6fe
> [  113.495140]  [<ffffffff814258c8>] ? kernfs_fop_read+0x3ab/0x3ab
> [  113.495143]  [<ffffffff813442fd>] vfs_open+0x179/0x186
> [  113.495156]  [<ffffffff81363618>] path_openat+0x198c/0x1c58
> [  113.495161]  [<ffffffff81d05cc7>] ? depot_save_stack+0x13c/0x390
> [  113.495164]  [<ffffffff813347b1>] ? save_stack+0xc4/0xce
> [  113.495167]  [<ffffffff81361c8c>] ? filename_mountpoint+0x17e/0x17e
>
> dmesg-quantal-ivb41-16:20160812160241:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  105.110247] init: Failed to create pty - disabling logging for job
> [  105.110381] init: Temporary process spawn error: No such file or
> directory
> [  106.640168] ==============================
> ===============================================
> [  106.640172] BUG anon_vma_chain (Not tainted): Poison overwritten
> [  106.640174] ------------------------------
> -----------------------------------------------
> [  106.640174] [  106.640174] Disabling lock debugging due to kernel taint
> [  106.640178] INFO: 0xffff880008d8eb75-0xffff880008d8eb77. First byte
> 0x1 instead of 0x6b
> [  106.640187] INFO: Allocated in anon_vma_prepare+0x6b/0x2db age=138
> cpu=0 pid=415
> [  106.640223] INFO: Freed in qlist_free_all+0x33/0xac age=26 cpu=0 pid=239
> [  106.640269] INFO: Slab 0xffffea0000236380 objects=19 used=19 fp=0x
>     (null) flags=0x4000000000004080
> [  106.640271] INFO: Object 0xffff880008d8eb68 @offset=2920
> fp=0xffff880008d8f528
> [  106.640271] [  106.640275] Redzone ffff880008d8eb60: bb bb bb bb bb bb
> bb bb                          ........
> [  106.640278] Object ffff880008d8eb68: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 01 c0 90  kkkkkkkkkkkkk...
> [  106.640281] Object ffff880008d8eb78: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  106.640284] Object ffff880008d8eb88: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  106.640287] Object ffff880008d8eb98: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
> [  106.640289] Redzone ffff880008d8eba8: bb bb bb bb bb bb bb bb
>                 ........
> [  106.640292] Padding ffff880008d8ecf4: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a
> 5a              ZZZZZZZZZZZZ
> [  106.640296] CPU: 0 PID: 398 Comm: ifup Tainted: G    B
>  4.7.0-05999-g80a9201 #1
> [  106.640298] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> Debian-1.8.2-1 04/01/2014
> [  106.640304]  0000000000000000 ffff8800088bf6d8 ffffffff81c91ab5
> ffff8800088bf708
> [  106.640308]  ffffffff81330f07 ffff880008d8eb75 000000000000006b
> ffff8800110131c0
> [  106.640311]  ffff880008d8eb77 ffff8800088bf758 ffffffff81330fac
> ffffffff83592f26
> [  106.640312] Call Trace:
> [  106.640317]  [<ffffffff81c91ab5>] dump_stack+0x19/0x1b
> [  106.640321]  [<ffffffff81330f07>] print_trailer+0x15b/0x164
> [  106.640324]  [<ffffffff81330fac>] check_bytes_and_report+0x9c/0xef
> [  106.640327]  [<ffffffff8133194d>] check_object+0x12f/0x1fb
> [  106.640330]  [<ffffffff813153ea>] ? anon_vma_prepare+0x6b/0x2db
> [  106.640334]  [<ffffffff81331f00>] alloc_debug_processing+0x7e/0x10d
> [  106.640338]  [<ffffffff8133211b>] ___slab_alloc+0x18c/0x31e
> [  106.640340]  [<ffffffff813153ea>] ? anon_vma_prepare+0x6b/0x2db
> [  106.640343]  [<ffffffff813153ea>] ? anon_vma_prepare+0x6b/0x2db
> [  106.640347]  [<ffffffff813322c3>] __slab_alloc+0x16/0x2a
> [  106.640350]  [<ffffffff813322c3>] ? __slab_alloc+0x16/0x2a
> [  106.640353]  [<ffffffff81332b53>] kmem_cache_alloc+0x50/0xb6
> [  106.640356]  [<ffffffff813153ea>] anon_vma_prepare+0x6b/0x2db
> [  106.640360]  [<ffffffff81304113>] handle_mm_fault+0xcf6/0x11bb
> [  106.640363]  [<ffffffff8130341d>] ? apply_to_page_range+0x2fb/0x2fb
> [  106.640367]  [<ffffffff8130e21e>] ? SyS_munmap+0x81/0x81
> [  106.640372]  [<ffffffff810e82be>] ? arch_get_unmapped_area+0x39c/0x39c
>
> dmesg-quantal-ivb41-26:20160812160257:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  111.995978] init: Failed to create pty - disabling logging for job
> [  111.996117] init: Temporary process spawn error: No such file or
> directory
> [  114.698502] ==============================
> ===============================================
> [  114.698515] BUG vm_area_struct (Not tainted): Poison overwritten
> [  114.698516] ------------------------------
> -----------------------------------------------
> [  114.698516] [  114.698517] Disabling lock debugging due to kernel taint
> [  114.698521] INFO: 0xffff880008488a8c-0xffff880008488a8f. First byte
> 0x6a instead of 0x6b
> [  114.698579] INFO: Allocated in copy_process+0x2323/0x424c age=107 cpu=0
> pid=419
> [  114.698676] INFO: Freed in qlist_free_all+0x33/0xac age=11 cpu=0 pid=263
> [  114.698730] INFO: Slab 0xffffea0000212200 objects=15 used=15 fp=0x
>     (null) flags=0x4000000000004080
> [  114.698733] INFO: Object 0xffff880008488a80 @offset=2688
> fp=0xffff880008488220
> [  114.698733] [  114.698742] Redzone ffff880008488a78: bb bb bb bb bb bb
> bb bb                          ........
> [  114.698747] Object ffff880008488a80: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6a 01 80 e4  kkkkkkkkkkkkj...
> [  114.698749] Object ffff880008488a90: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  114.698752] Object ffff880008488aa0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-quantal-ivb41-42:20160812160302:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  106.294052] init: Failed to create pty - disabling logging for job
> [  106.294199] init: Temporary process spawn error: No such file or
> directory
> [  107.451301] ==============================
> ===============================================
> [  107.451306] BUG vm_area_struct (Not tainted): Poison overwritten
> [  107.451307] ------------------------------
> -----------------------------------------------
> [  107.451307] [  107.451308] Disabling lock debugging due to kernel taint
> [  107.451312] INFO: 0xffff88000914665c-0xffff88000914665f. First byte
> 0x6a instead of 0x6b
> [  107.451321] INFO: Allocated in copy_process+0x2323/0x424c age=140 cpu=0
> pid=1
> [  107.451353] INFO: Freed in qlist_free_all+0x33/0xac age=67 cpu=0 pid=261
> [  107.451397] INFO: Slab 0xffffea0000245180 objects=15 used=15 fp=0x
>     (null) flags=0x4000000000004080
> [  107.451399] INFO: Object 0xffff880009146650 @offset=1616
> fp=0xffff880009147d58
> [  107.451399] [  107.451403] Redzone ffff880009146648: bb bb bb bb bb bb
> bb bb                          ........
> [  107.451406] Object ffff880009146650: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6a 01 e0 e5  kkkkkkkkkkkkj...
> [  107.451409] Object ffff880009146660: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  107.451411] Object ffff880009146670: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-quantal-ivb41-52:20160812160241:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  106.678891] irda_setsockopt: not allowed to set MAXSDUSIZE for this
> socket type!
> [  106.749546] power_supply test_ac: prop ONLINE=1
> [  107.430823] ==============================
> ===============================================
> [  107.434407] BUG vm_area_struct (Not tainted): Poison overwritten
> [  107.436760] ------------------------------
> -----------------------------------------------
> [  107.436760] [  107.449972] Disabling lock debugging due to kernel taint
> [  107.452404] INFO: 0xffff880009bd2874-0xffff880009bd2877. First byte
> 0x6a instead of 0x6b
> [  107.456114] INFO: Allocated in mmap_region+0x33a/0xa41 age=359 cpu=0
> pid=440
> [  107.500267] INFO: Freed in qlist_free_all+0x33/0xac age=58 cpu=0 pid=264
> [  107.547459] INFO: Slab 0xffffea000026f480 objects=15 used=15 fp=0x
>     (null) flags=0x4000000000004080
> [  107.551406] INFO: Object 0xffff880009bd2868 @offset=2152
> fp=0xffff880009bd3928
> [  107.551406] [  107.562146] Redzone ffff880009bd2860: bb bb bb bb bb bb
> bb bb                          ........
> [  107.565909] Object ffff880009bd2868: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6a 01 80 fc  kkkkkkkkkkkkj...
> [  107.573610] Object ffff880009bd2878: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  107.576946] Object ffff880009bd2888: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-quantal-ivb41-71:20160812160239:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  103.201437] power_supply test_usb: POWER_SUPPLY_NAME=test_usb
> [  103.201462] power_supply test_usb: prop ONLINE=1
> [  104.201388] ==============================
> ===============================================
> [  104.201393] BUG skbuff_head_cache (Not tainted): Poison overwritten
> [  104.201394] ------------------------------
> -----------------------------------------------
> [  104.201394] [  104.201395] Disabling lock debugging due to kernel taint
> [  104.201397] INFO: 0xffff88000a459b8c-0xffff88000a459b8f. First byte
> 0x6d instead of 0x6b
> [  104.201406] INFO: Allocated in __alloc_skb+0xad/0x498 age=169 cpu=0
> pid=1
> [  104.201451] INFO: Freed in qlist_free_all+0x33/0xac age=13 cpu=0 pid=254
> [  104.201493] INFO: Slab 0xffffea0000291600 objects=10 used=10 fp=0x
>     (null) flags=0x4000000000004080
> [  104.201495] INFO: Object 0xffff88000a459b80 @offset=7040
> fp=0xffff88000a458980
> [  104.201495] [  104.201500] Redzone ffff88000a459b00: bb bb bb bb bb bb
> bb bb bb bb bb bb bb bb bb bb  ................
> [  104.201503] Redzone ffff88000a459b10: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.201506] Redzone ffff88000a459b20: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.201508] Redzone ffff88000a459b30: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.201511] Redzone ffff88000a459b40: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.201513] Redzone ffff88000a459b50: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.201516] Redzone ffff88000a459b60: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.201519] Redzone ffff88000a459b70: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.201521] Object ffff88000a459b80: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6d 01 e0 af  kkkkkkkkkkkkm...
> [  104.201524] Object ffff88000a459b90: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  104.201527] Object ffff88000a459ba0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-quantal-ivb41-96:20160812160242:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> udevd[310]: failed to execute '/sbin/modprobe' '/sbin/modprobe -bv
> pci:v00001234d00001111sv00001AF4sd00001100bc03sc00i00': No such file or
> directory
> udevd[358]: failed to execute '/sbin/modprobe' '/sbin/modprobe -bv
> dmi:bvnSeaBIOS:bvrDebian-1.8.2-1:bd04/01/2014:svnQEMU:pnStan
> dardPC(i440FX+PIIX,1996):pvrpc-i440fx-2.4:cvnQEMU:ct1:cvrpc-i440fx-2.4:':
> No such file or directory
> [  110.688412] ==============================
> ===============================================
> [  110.692354] BUG names_cache (Not tainted): Poison overwritten
> [  110.694901] ------------------------------
> -----------------------------------------------
> [  110.694901] [  110.699914] Disabling lock debugging due to kernel taint
> [  110.702057] INFO: 0xffff880009a4b58c-0xffff880009a4b58f. First byte
> 0x69 instead of 0x6b
> [  110.705346] INFO: Allocated in getname_flags+0x5a/0x35c age=85 cpu=0
> pid=253
> [  110.727505] INFO: Freed in qlist_free_all+0x33/0xac age=8 cpu=0 pid=1
> [  110.766664] INFO: Slab 0xffffea0000269200 objects=7 used=7 fp=0x
>   (null) flags=0x4000000000004080
> [  110.770745] INFO: Object 0xffff880009a4b580 @offset=13696
> fp=0xffff880009a4c740
> [  110.770745] [  110.777537] Redzone ffff880009a4b540: bb bb bb bb bb bb
> bb bb bb bb bb bb bb bb bb bb  ................
> [  110.789632] Redzone ffff880009a4b550: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  110.805843] Redzone ffff880009a4b560: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  110.809851] Redzone ffff880009a4b570: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  110.813955] Object ffff880009a4b580: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 69 01 00 a7  kkkkkkkkkkkki...
> [  110.818081] Object ffff880009a4b590: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  110.825439] Object ffff880009a4b5a0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-vm-ivb41-quantal-x86_64-14:20160812160512:x86_64-randc
> onfig-s0-08040601:4.7.0-05999-g80a9201:1
>
> udevd[350]: failed to execute '/sbin/modprobe' '/sbin/modprobe -bv
> input:b0011v0001p0001eAB41-e0,1,4,11,14,k71,72,73,74,75,76,7
> 7,79,7A,7B,7C,7D,7E,7F,80,8C,8E,8F,9B,9C,9D,9E,9F,A3,A4,A5,A
> 6,AC,AD,B7,B8,B9,D9,E2,ram4,l0,1,2,sfw': No such file or directory
> udevd[349]: failed to execute '/sbin/modprobe' '/sbin/modprobe -bv
> acpi:PNP0F13:': No such file or directory
> [   72.009404] ==============================
> ===============================================
> [   72.012878] BUG kmalloc-512 (Not tainted): Poison overwritten
> [   72.015063] ------------------------------
> -----------------------------------------------
> [   72.015063] [   72.019443] Disabling lock debugging due to kernel taint
> [   72.021499] INFO: 0xffff880017642a35-0xffff880017642a37. First byte
> 0x1 instead of 0x6b
> [   72.037465] INFO: Allocated in load_elf_phdrs+0x9a/0xf4 age=169 cpu=0
> pid=356
> [   72.065799] INFO: Freed in qlist_free_all+0x33/0xac age=67 cpu=0 pid=265
> [   72.121094] INFO: Slab 0xffffea00005d9080 objects=9 used=9 fp=0x
>   (null) flags=0x4000000000004080
> [   72.125452] INFO: Object 0xffff880017642a28 @offset=2600 fp=0x
> (null)
> [   72.125452] [   72.130200] Redzone ffff880017642a20: bb bb bb bb bb bb
> bb bb                          ........
> [   72.134294] Object ffff880017642a28: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 01 80 b1  kkkkkkkkkkkkk...
> [   72.138544] Object ffff880017642a38: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [   72.142802] Object ffff880017642a48: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-vm-ivb41-quantal-x86_64-1:20160812160325:x86_64-randco
> nfig-s0-08040601:4.7.0-05999-g80a9201:1
>
> [   75.545932] ipconfig: ipddp0: socket(AF_INET): Address family not
> supported by protocol
> [   75.551674] ipconfig: no devices to configure
> [   75.558551] /usr/share/initramfs-tools/scripts/functions: line 491:
> /run/net-eth0.conf: No such file or directory
> !!! IP-Config: Auto-configuration of network failed !!!
> [   75.860942] !!! IP-Config: Auto-configuration of network failed !!!
> error: 'rc.local' exited outside the expected code flow.
> [   75.931858] init: Failed to create pty - disabling logging for job
> [   75.933512] init: Temporary process spawn error: No such file or
> directory
>
> dmesg-yocto-ivb41-105:20160812160231:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  106.928062] blk_update_request: I/O error, dev fd0, sector 0
> [  106.929740] floppy: error -5 while reading block 0
> [  107.012218] ==============================
> ===============================================
> [  107.019136] BUG kmalloc-256 (Not tainted): Poison overwritten
> [  107.020787] ------------------------------
> -----------------------------------------------
> [  107.020787] [  107.024336] Disabling lock debugging due to kernel taint
> [  107.025926] INFO: 0xffff880008ca2e54-0xffff880008ca2e57. First byte
> 0x6c instead of 0x6b
> [  107.028595] INFO: Allocated in do_execveat_common+0x268/0x11d2 age=281
> cpu=0 pid=352
> [  107.076371] INFO: Freed in qlist_free_all+0x33/0xac age=227 cpu=0
> pid=291
> [  107.149193] INFO: Slab 0xffffea0000232880 objects=13 used=13 fp=0x
>     (null) flags=0x4000000000004080
> [  107.167264] INFO: Object 0xffff880008ca2e48 @offset=3656
> fp=0xffff880008ca3c88
> [  107.167264] [  107.170622] Redzone ffff880008ca2e40: bb bb bb bb bb bb
> bb bb                          ........
> [  107.173376] Object ffff880008ca2e48: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6c 01 00 ae  kkkkkkkkkkkkl...
> [  107.195350] Object ffff880008ca2e58: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  107.198226] Object ffff880008ca2e68: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-yocto-ivb41-108:20160812160251:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> /etc/rcS.d/S00fbsetup: line 3: /sbin/modprobe: not found
> Starting udev
> [  110.935770] ==============================
> ====================================
> [  110.938593] BUG: KASAN: use-after-free in vma_interval_tree_compute_subtree_last+0x5f/0xcc
> at addr ffff8800087f4f20
> [  110.941666] Read of size 8 by task udevd/440
> [  110.956256] CPU: 0 PID: 440 Comm: udevd Not tainted
> 4.7.0-05999-g80a9201 #1
> [  110.958363] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> Debian-1.8.2-1 04/01/2014
> [  110.961354]  0000000000000000 ffff880008bbf680 ffffffff81c91ab5
> ffff880008bbf6f8
> [  110.964325]  ffffffff8133576b ffffffff812f6c1b 0000000000000246
> 000000010013000b
> [  110.967282]  0000000000000246 0000000000000000 ffff880008bbf7e0
> ffffffff812ff9dc
> [  110.970325] Call Trace:
> [  110.971562]  [<ffffffff81c91ab5>] dump_stack+0x19/0x1b
> [  110.973253]  [<ffffffff8133576b>] kasan_report+0x319/0x553
> [  110.975079]  [<ffffffff812f6c1b>] ? vma_interval_tree_compute_subt
> ree_last+0x5f/0xcc
> [  110.977922]  [<ffffffff812ff9dc>] ? unmap_page_range+0x4f5/0x949
> [  110.979838]  [<ffffffff813359fb>] __asan_report_load8_noabort+0x14/0x16
> [  110.981848]  [<ffffffff812f6c1b>] vma_interval_tree_compute_subt
> ree_last+0x5f/0xcc
> [  110.984734]  [<ffffffff812f6cb1>] vma_interval_tree_augment_prop
> agate+0x29/0x75
> [  110.987552]  [<ffffffff812f78b3>] vma_interval_tree_remove+0x5e2/0x608
> [  110.989359]  [<ffffffff81307c85>] __remove_shared_vm_struct+0x7b/0x82
> [  110.991151]  [<ffffffff81309084>] unlink_file_vma+0x82/0x93
> [  110.992789]  [<ffffffff812fe80c>] free_pgtables+0xf0/0x13e
> [  110.994416]  [<ffffffff8130bb3a>] exit_mmap+0x13e/0x2b2
> [  110.995989]  [<ffffffff8130b9fc>] ? split_vma+0x96/0x96
> [  110.997715]  [<ffffffff811f1079>] ? ___might_sleep+0xa4/0x321
> [  110.999554]  [<ffffffff811a71bd>] __mmput+0x58/0x181
> [  111.001251]  [<ffffffff811a730e>] mmput+0x28/0x2b
> [  111.002907]  [<ffffffff81353b6c>] flush_old_exec+0x1102/0x124a
> [  111.004747]  [<ffffffff813e53c0>] load_elf_binary+0x776/0x357c
> [  111.006622]  [<ffffffff813e4c4a>] ? elf_core_dump+0x30d0/0x30d0
> [  111.008547]  [<ffffffff813549eb>] search_binary_handler+0x100/0x1fb
> [  111.010493]  [<ffffffff813e11b4>] load_script+0x4b8/0x506
> [  111.012285]  [<ffffffff813e0cfc>] ? compat_SyS_ioctl+0x184d/0x184d
> [  111.043190]  [<ffffffff811f1079>] ? ___might_sleep+0xa4/0x321
> [  111.044879]  [<ffffffff811f144c>] ? __might_sleep+0x156/0x162
> [  111.046565]  [<ffffffff81351535>] ? copy_strings+0x467/0x52d
> [  111.061417]  [<ffffffff813549eb>] search_binary_handler+0x100/0x1fb
> [  111.063414]  [<ffffffff81355912>] do_execveat_common+0xe2c/0x11d2
> [  111.065464]  [<ffffffff81354ae6>] ? search_binary_handler+0x1fb/0x1fb
> [  111.067347]  [<ffffffff81332bab>] ? kmem_cache_alloc+0xa8/0xb6
> [  111.069035]  [<ffffffff8135c29a>] ? getname_flags+0x337/0x35c
> [  111.070721]  [<ffffffff82c80830>] ? ptregs_sys_vfork+0x10/0x10
> [  111.072417]  [<ffffffff81355cd6>] do_execve+0x1e/0x20
> [  111.073977]  [<ffffffff813564b5>] SyS_execve+0x25/0x29
> [  111.088763]  [<ffffffff81002ab8>] do_syscall_64+0x1be/0x1fa
> [  111.090635]  [<ffffffff8111d254>] ? do_page_fault+0x22/0x27
> [  111.092428]  [<ffffffff82c80722>] entry_SYSCALL64_slow_path+0x25/0x25
> [  111.094213] Object at ffff8800087f4eb0, in cache vm_area_struct
> [  111.095899] Object allocated with size 184 bytes.
> [  111.097396] Allocation:
> [  111.098505] PID = 307
> [  111.099587]  [<ffffffff810f473d>] save_stack_trace+0x25/0x40
> [  111.108858]  [<ffffffff81334733>] save_stack+0x46/0xce
> [  111.110727]  [<ffffffff81334d14>] kasan_kmalloc+0xb7/0xc6
> [  111.112645]  [<ffffffff81334d35>] kasan_slab_alloc+0x12/0x14
> [  111.114589]  [<ffffffff81330102>] slab_post_alloc_hook+0x38/0x45
> [  111.116633]  [<ffffffff81332bab>] kmem_cache_alloc+0xa8/0xb6
> [  111.118546]  [<ffffffff811a9b50>] copy_process+0x2323/0x424c
> [  111.134489]  [<ffffffff811abe13>] _do_fork+0x159/0x3d9
> [  111.136389]  [<ffffffff811ac105>] SyS_clone+0x14/0x16
> [  111.138219]  [<ffffffff81002ab8>] do_syscall_64+0x1be/0x1fa
> [  111.140170]  [<ffffffff82c80722>] return_from_SYSCALL_64+0x0/0x6a
> [  111.142225] Memory state around the buggy address:
> [  111.143913]  ffff8800087f4e00: fc fc fc fc fc fc fc fc fc fc fc fc fc
> fc fc fc
>
> dmesg-yocto-ivb41-111:20160812160248:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> Starting udev
> [  112.488293] power_supply test_ac: uevent
> ** 127 printk messages dropped ** [  112.617229]  [<ffffffff811aa2f2>]
> copy_process+0x2ac5/0x424c
> [  112.617233]  [<ffffffff811abe13>] _do_fork+0x159/0x3d9
> [  112.617236]  [<ffffffff811ac105>] SyS_clone+0x14/0x16
> [  112.617239]  [<ffffffff81002ab8>] do_syscall_64+0x1be/0x1fa
> ** 222 printk messages dropped ** [  112.617893]  [<ffffffff811ade96>] ?
> task_stopped_code+0xcb/0xcb
> ** 1244 printk messages dropped **
> dmesg-yocto-ivb41-115:20160812160246:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> /etc/rcS.d/S00fbsetup: line 3: /sbin/modprobe: not found
> Starting udev
> [  112.596067] ==============================
> ===============================================
> [  112.598922] BUG names_cache (Not tainted): Poison overwritten
> [  112.600657] ------------------------------
> -----------------------------------------------
> [  112.600657] [  112.618436] Disabling lock debugging due to kernel taint
> [  112.620090] INFO: 0xffff880009bea3cc-0xffff880009bea3cf. First byte
> 0x6e instead of 0x6b
> [  112.622909] INFO: Allocated in getname_flags+0x5a/0x35c age=71 cpu=0
> pid=285
> [  112.657427] INFO: Freed in qlist_free_all+0x33/0xac age=1 cpu=0 pid=452
> [  112.705095] INFO: Slab 0xffffea000026fa00 objects=7 used=7 fp=0x
>   (null) flags=0x4000000000004080
> [  112.708087] INFO: Object 0xffff880009bea3c0 @offset=9152 fp=0x
> (null)
> [  112.708087] [  112.724701] Redzone ffff880009bea380: bb bb bb bb bb bb
> bb bb bb bb bb bb bb bb bb bb  ................
> [  112.756566] Redzone ffff880009bea390: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  112.759561] Redzone ffff880009bea3a0: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  112.775649] Redzone ffff880009bea3b0: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  112.778746] Object ffff880009bea3c0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6e 01 40 d5  kkkkkkkkkkkkn.@.
> [  112.781743] Object ffff880009bea3d0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  112.784844] Object ffff880009bea3e0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-yocto-ivb41-122:20160812160234:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  103.749230] power_supply test_battery: prop MANUFACTURER=Linux
> [  104.141979] power_supply test_battery: prop
> SERIAL_NUMBER=4.7.0-05999-g80a9201
> [  104.484013] ==============================
> ===============================================
> [  104.484018] BUG names_cache (Not tainted): Poison overwritten
> [  104.484019] ------------------------------
> -----------------------------------------------
> [  104.484019] [  104.484020] Disabling lock debugging due to kernel taint
> [  104.484023] INFO: 0xffff880007f3474d-0xffff880007f3474f. First byte
> 0x1 instead of 0x6b
> [  104.484032] INFO: Allocated in getname_flags+0x5a/0x35c age=155 cpu=0
> pid=529
> [  104.484064] INFO: Freed in qlist_free_all+0x33/0xac age=16 cpu=0 pid=592
> [  104.484104] INFO: Slab 0xffffea00001fcc00 objects=7 used=7 fp=0x
>   (null) flags=0x4000000000004080
> [  104.484106] INFO: Object 0xffff880007f34740 @offset=18240 fp=0x
>   (null)
> [  104.484106] [  104.484111] Redzone ffff880007f34700: bb bb bb bb bb bb
> bb bb bb bb bb bb bb bb bb bb  ................
> [  104.484114] Redzone ffff880007f34710: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.484117] Redzone ffff880007f34720: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.484120] Redzone ffff880007f34730: bb bb bb bb bb bb bb bb bb bb bb
> bb bb bb bb bb  ................
> [  104.484122] Object ffff880007f34740: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 01 60 f7  kkkkkkkkkkkkk.`.
> [  104.484125] Object ffff880007f34750: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  104.484128] Object ffff880007f34760: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-yocto-ivb41-132:20160812160253:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> /etc/rcS.d/S00fbsetup: line 3: /sbin/modprobe: not found
> Starting udev
> [  112.029713] ==============================
> ====================================
> [  112.032515] BUG: KASAN: use-after-free in __rb_insert_augmented+0x343/0x59f
> at addr ffff8800090af768
> [  112.035635] Read of size 8 by task mount.sh/466
> [  112.037302] CPU: 0 PID: 466 Comm: mount.sh Not tainted
> 4.7.0-05999-g80a9201 #1
> [  112.039950] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> Debian-1.8.2-1 04/01/2014
> [  112.043015]  0000000000000000 ffff88000806fb58 ffffffff81c91ab5
> ffff88000806fbd0
> [  112.046337]  ffffffff8133576b ffffffff81c9eeac 0000000000000246
> ffff8800081d5b88
> [  112.049624]  ffff88000806fbc0 ffffffff81334d14 024000c0081d44e8
> 0000000000000001
> [  112.055593] Call Trace:
> [  112.056850]  [<ffffffff81c91ab5>] dump_stack+0x19/0x1b
> [  112.061900]  [<ffffffff8133576b>] kasan_report+0x319/0x553
> [  112.063705]  [<ffffffff81c9eeac>] ? __rb_insert_augmented+0x343/0x59f
> [  112.065686]  [<ffffffff81334d14>] ? kasan_kmalloc+0xb7/0xc6
> [  112.072750]  [<ffffffff813359fb>] __asan_report_load8_noabort+0x14/0x16
> [  112.074793]  [<ffffffff81c9eeac>] __rb_insert_augmented+0x343/0x59f
> [  112.076784]  [<ffffffff812f6cfd>] ? vma_interval_tree_augment_prop
> agate+0x75/0x75
> [  112.079403]  [<ffffffff812f7c25>] vma_interval_tree_insert_after
> +0x1b6/0x1c3
> [  112.081516]  [<ffffffff811a9e51>] copy_process+0x2624/0x424c
> [  112.083461]  [<ffffffff811a782d>] ? __cleanup_sighand+0x23/0x23
> [  112.085280]  [<ffffffff81380da8>] ? put_unused_fd+0x6f/0x6f
> [  112.087025]  [<ffffffff811f1079>] ? ___might_sleep+0xa4/0x321
> [  112.088807]  [<ffffffff811abe13>] _do_fork+0x159/0x3d9
> [  112.090562]  [<ffffffff811abcba>] ? fork_idle+0x1ed/0x1ed
> [  112.092348]  [<ffffffff813596a7>] ? __do_pipe_flags+0x1aa/0x1aa
> [  112.094270]  [<ffffffff8111d106>] ? __do_page_fault+0x519/0x624
> [  112.096169]  [<ffffffff82c80800>] ? ptregs_sys_rt_sigreturn+0x10/0x10
> [  112.098134]  [<ffffffff811ac105>] SyS_clone+0x14/0x16
> [  112.099854]  [<ffffffff81002ab8>] do_syscall_64+0x1be/0x1fa
> [  112.101750]  [<ffffffff8111d254>] ? do_page_fault+0x22/0x27
> [  112.103686]  [<ffffffff82c80722>] entry_SYSCALL64_slow_path+0x25/0x25
> [  112.105501] Object at ffff8800090af710, in cache vm_area_struct
> [  112.107338] Object allocated with size 184 bytes.
> [  112.110479] Allocation:
> [  112.111710] PID = 458
> [  112.112890]  [<ffffffff810f473d>] save_stack_trace+0x25/0x40
> [  112.114854]  [<ffffffff81334733>] save_stack+0x46/0xce
> [  112.116744]  [<ffffffff81334d14>] kasan_kmalloc+0xb7/0xc6
> [  112.118671]  [<ffffffff81334d35>] kasan_slab_alloc+0x12/0x14
> [  112.122769]  [<ffffffff81330102>] slab_post_alloc_hook+0x38/0x45
> [  112.124716]  [<ffffffff81332bab>] kmem_cache_alloc+0xa8/0xb6
> [  112.143510]  [<ffffffff811a9b50>] copy_process+0x2323/0x424c
> [  112.145784]  [<ffffffff811abe13>] _do_fork+0x159/0x3d9
> [  112.147724]  [<ffffffff811ac105>] SyS_clone+0x14/0x16
> [  112.149579]  [<ffffffff81002ab8>] do_syscall_64+0x1be/0x1fa
> [  112.151508]  [<ffffffff82c80722>] return_from_SYSCALL_64+0x0/0x6a
> [  112.153543] Memory state around the buggy address:
> [  112.155232]  ffff8800090af600: fc fc fc fc fc fc fc fc fc fc fc fc fc
> fc fc fc
>
> dmesg-yocto-ivb41-133:20160812160230:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> /etc/rcS.d/S00fbsetup: line 3: /sbin/modprobe: not found
> Starting udev
> [  106.248948] ==============================
> ====================================
> [  106.251786] BUG: KASAN: use-after-free in get_page_from_freelist+0x49/0xb73
> at addr ffff88000840fa40
> [  106.272766] Read of size 8 by task expr/528
> [  106.274336] page:ffffea00002103c0 count:0 mapcount:0 mapping:
> (null) index:0x0
> [  106.277274] flags: 0x4000000000000000()
> [  106.278619] page dumped because: kasan: bad access detected
> [  106.280250] CPU: 0 PID: 528 Comm: expr Not tainted 4.7.0-05999-g80a9201
> #1
> [  106.282090] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> Debian-1.8.2-1 04/01/2014
> [  106.284933]  0000000000000000 ffff88000840f778 ffffffff81c91ab5
> ffff88000840f7f0
> [  106.301199]  ffffffff8133585b ffffffff812c89be 0000000000000246
> 0000000000000001
> [  106.304352]  ffffffff83e63818 0000000000000000 ffffea00000fbc60
> 0000000000000000
> [  106.307318] Call Trace:
> [  106.308442]  [<ffffffff81c91ab5>] dump_stack+0x19/0x1b
> [  106.310001]  [<ffffffff8133585b>] kasan_report+0x409/0x553
> [  106.324707]  [<ffffffff812c89be>] ? get_page_from_freelist+0x49/0xb73
> [  106.326679]  [<ffffffff813359fb>] __asan_report_load8_noabort+0x14/0x16
> [  106.328639]  [<ffffffff812c89be>] get_page_from_freelist+0x49/0xb73
> [  106.330529]  [<ffffffff812c7e42>] ? __rmqueue+0x7f/0x32f
> [  106.332117]  [<ffffffff812ca07d>] __alloc_pages_nodemask+0x2b8/0x1199
> [  106.333907]  [<ffffffff812c91dd>] ? get_page_from_freelist+0x868/0xb73
> [  106.335699]  [<ffffffff812c9dc5>] ? gfp_pfmemalloc_allowed+0x11/0x11
> [  106.350531]  [<ffffffff8133499c>] ? kasan_alloc_pages+0x39/0x3b
>
> dmesg-yocto-ivb41-135:20160812160229:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> /etc/rcS.d/S00fbsetup: line 3: /sbin/modprobe: not found
> Starting udev
> [  105.892255] ==============================
> ===============================================
> [  105.901019] BUG kmalloc-128 (Not tainted): Poison overwritten
> [  105.902922] ------------------------------
> -----------------------------------------------
> [  105.902922] [  105.906433] Disabling lock debugging due to kernel taint
> [  105.914324] INFO: 0xffff88000845f5b4-0xffff88000845f5b7. First byte
> 0x6d instead of 0x6b
> [  105.919465] INFO: Allocated in kzalloc+0xe/0x10 age=148 cpu=0 pid=268
> [  105.962987] INFO: Freed in qlist_free_all+0x33/0xac age=97 cpu=0 pid=470
> [  106.001540] INFO: Slab 0xffffea00002117c0 objects=8 used=8 fp=0x
>   (null) flags=0x4000000000000080
> [  106.012655] INFO: Object 0xffff88000845f5a8 @offset=1448
> fp=0xffff88000845f008
> [  106.012655] [  106.016241] Redzone ffff88000845f5a0: bb bb bb bb bb bb
> bb bb                          ........
> [  106.055850] Object ffff88000845f5a8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6d 01 60 e2  kkkkkkkkkkkkm.`.
> [  106.058718] Object ffff88000845f5b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  106.070047] Object ffff88000845f5c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>
> dmesg-yocto-ivb41-13:20160812160250:x86_64-randconfig-s0-
> 08040601:4.7.0-05999-g80a9201:1
>
> [  107.789093] power_supply test_ac: uevent
> [  107.879899] power_supply test_ac: POWER_SUPPLY_NAME=test_ac
> [  108.143440] ==============================
> ===============================================
> [  108.143454] BUG anon_vma_chain (Not tainted): Poison overwritten
> [  108.143456] ------------------------------
> -----------------------------------------------
> [  108.143456] [  108.143460] Disabling lock debugging due to kernel taint
> [  108.143465] INFO: 0xffff8800081d5054-0xffff8800081d5057. First byte
> 0x6c instead of 0x6b
> [  108.143524] INFO: Allocate...