syzbot


INFO: task hung in kern_unmount

Status: auto-closed as invalid on 2019/03/23 15:31
First crash: 2089d, last: 2089d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in kern_unmount fs 1 2298d 2297d 0/28 closed as invalid on 2018/03/27 11:08
android-49 INFO: task hung in kern_unmount 6 1705d 1887d 0/3 auto-closed as invalid on 2020/02/10 14:31

Sample crash report:
IPv6: Can't replace route, no match found
IPv6: Can't replace route, no match found
netlink: 8 bytes leftover after parsing attributes in process `syz-executor2'.
IPv6: Can't replace route, no match found
INFO: task kworker/1:0:18 blocked for more than 140 seconds.
      Not tainted 4.14.71+ #8
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:0     D29264    18      2 0x80000000
Workqueue: events proc_cleanup_work
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 schedule_timeout+0x710/0xe60 kernel/time/timer.c:1721
 do_wait_for_common kernel/sched/completion.c:91 [inline]
 __wait_for_common kernel/sched/completion.c:112 [inline]
 wait_for_common+0x3bc/0x4e0 kernel/sched/completion.c:123
 __wait_rcu_gp+0x250/0x3a0 kernel/rcu/update.c:413
 synchronize_rcu.part.43+0xd2/0xe0 kernel/rcu/tree_plugin.h:764
 kern_unmount+0x53/0xc0 fs/namespace.c:3358
 process_one_work+0x86e/0x15c0 kernel/workqueue.c:2114
 worker_thread+0xdc/0x1000 kernel/workqueue.c:2248
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
INFO: task syz-executor4:11988 blocked for more than 140 seconds.
      Not tainted 4.14.71+ #8
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D28112 11988   1849 0x80000000
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 schedule_timeout+0x710/0xe60 kernel/time/timer.c:1721
 do_wait_for_common kernel/sched/completion.c:91 [inline]
 __wait_for_common kernel/sched/completion.c:112 [inline]
 wait_for_common+0x3bc/0x4e0 kernel/sched/completion.c:123
 exit_aio+0x279/0x2f0 fs/aio.c:918
 __mmput kernel/fork.c:926 [inline]
 mmput+0x80/0x350 kernel/fork.c:950
 exit_mm kernel/exit.c:544 [inline]
 do_exit+0x83b/0x2800 kernel/exit.c:852
 do_group_exit+0x100/0x2e0 kernel/exit.c:968
 get_signal+0x4e5/0x1470 kernel/signal.c:2348
 do_signal+0x8f/0x1660 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x116/0x150 arch/x86/entry/common.c:159
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:267 [inline]
 do_syscall_64+0x35d/0x4b0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457679
RSP: 002b:00007fac5c43ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000072bf08 RCX: 0000000000457679
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000072bf08
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072bf0c
R13: 00007ffcd044a9df R14: 00007fac5c43d9c0 R15: 0000000000000000
INFO: task syz-executor4:19394 blocked for more than 140 seconds.
      Not tainted 4.14.71+ #8
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D28728 19394   1849 0x80000002
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 schedule_timeout+0x710/0xe60 kernel/time/timer.c:1721
 do_wait_for_common kernel/sched/completion.c:91 [inline]
 __wait_for_common kernel/sched/completion.c:112 [inline]
 wait_for_common+0x3bc/0x4e0 kernel/sched/completion.c:123
 __wait_rcu_gp+0x250/0x3a0 kernel/rcu/update.c:413
 synchronize_rcu.part.43+0xd2/0xe0 kernel/rcu/tree_plugin.h:764
 synchronize_net+0x3a/0x40 net/core/dev.c:8188
 packet_release+0x796/0xb60 net/packet/af_packet.c:3043
 __sock_release+0xce/0x250 net/socket.c:602
 sock_close+0x15/0x20 net/socket.c:1138
 __fput+0x25e/0x6f0 fs/file_table.c:210
 task_work_run+0x116/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x8f8/0x2800 kernel/exit.c:865
 do_group_exit+0x100/0x2e0 kernel/exit.c:968
 get_signal+0x4e5/0x1470 kernel/signal.c:2348
 do_signal+0x8f/0x1660 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x116/0x150 arch/x86/entry/common.c:159
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:267 [inline]
 do_syscall_64+0x35d/0x4b0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457679
RSP: 002b:00007fac5c43ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000072bf08 RCX: 0000000000457679
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000072bf08
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072bf0c
R13: 00007ffcd044a9df R14: 00007fac5c43d9c0 R15: 0000000000000000

Showing all locks held in the system:
2 locks held by kworker/1:0/18:
 #0:  ("events"){+.+.}, at: [<ffffffff887275d7>] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+.}, at: [<ffffffff8872760f>] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff88801e67>] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541
2 locks held by kworker/1:1/68:
 #0:  ("events"){+.+.}, at: [<ffffffff887275d7>] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+.}, at: [<ffffffff8872760f>] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089
2 locks held by getty/1759:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff893245e0>] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8931fb5f>] n_tty_read+0x1ff/0x15e0 drivers/tty/n_tty.c:2142
2 locks held by kworker/1:2/4482:
 #0:  ("events"){+.+.}, at: [<ffffffff887275d7>] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+.}, at: [<ffffffff8872760f>] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089
2 locks held by kworker/1:3/4673:
 #0:  ("events"){+.+.}, at: [<ffffffff887275d7>] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+.}, at: [<ffffffff8872760f>] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089
2 locks held by kworker/1:4/9431:
 #0:  ("events"){+.+.}, at: [<ffffffff887275d7>] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+.}, at: [<ffffffff8872760f>] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089
2 locks held by kworker/1:5/12159:
 #0:  ("events"){+.+.}, at: [<ffffffff887275d7>] process_one_work+0x787/0x15c0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+.}, at: [<ffffffff8872760f>] process_one_work+0x7bf/0x15c0 kernel/workqueue.c:2089
1 lock held by syz-executor4/19394:
 #0:  (&sb->s_type->i_mutex_key#9){+.+.}, at: [<ffffffff8988a294>] inode_lock include/linux/fs.h:713 [inline]
 #0:  (&sb->s_type->i_mutex_key#9){+.+.}, at: [<ffffffff8988a294>] __sock_release+0x84/0x250 net/socket.c:601

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.71+ #8
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 nmi_cpu_backtrace.cold.0+0x47/0x85 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline]
 watchdog+0x574/0xa70 kernel/hung_task.c:252
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 20730 Comm: syz-executor2 Not tainted 4.14.71+ #8
task: ffff8801c9060000 task.stack: ffff8801ca318000
RIP: 0033:0x40157b
RSP: 002b:00007f717add8690 EFLAGS: 00000282
RAX: 00000000d160596d RBX: 0000000000000007 RCX: 0000000000457679
RDX: 0000000000000000 RSI: 00007f717add86c0 RDI: 0000000000000007
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7cf0 R14: 00000000004c49b7 R15: 0000000000000000
FS:  00007f717add9700(0000) GS:ffff8801dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0aef23b140 CR3: 00000001d2eb6003 CR4: 00000000001606a0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/09/24 15:29 android-4.14 666c420fa3ea 2f485cdf .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.