audit: type=1400 audit(1536483376.571:22087): avc:  denied  { net_admin } for  pid=2112 comm="syz-executor0" capability=12  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1536483376.571:22088): avc:  denied  { net_admin } for  pid=2112 comm="syz-executor0" capability=12  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
INFO: task syz-executor4:19192 blocked for more than 140 seconds.
      Not tainted 4.9.125+ #89
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D29032 19192   5699 0x00000002
 ffff88019f2a8000 ffff8801d3f5b180 ffff8801d3f5b180 ffff8801abe28000
 ffff8801db721018 ffff8801b5a277a8 ffffffff8277d092 0000000000000000
 ffff88019f2a88b0 ffffed0033e55115 00ff88019f2a8000 ffff8801db7218f0
Call Trace:
 [<ffffffff8277e5bf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff8277ef43>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff82780bc6>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff82780bc6>] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621
 [<ffffffff81ccd878>] tty_release+0xa88/0xd00 drivers/tty/tty_io.c:1933
 [<ffffffff814f06f3>] __fput+0x263/0x700 fs/file_table.c:208
 [<ffffffff814f0c15>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff81138c4c>] task_work_run+0x10c/0x180 kernel/task_work.c:116
 [<ffffffff810e3cb7>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff810e3cb7>] do_exit+0x787/0x2750 kernel/exit.c:833
 [<ffffffff810ea111>] do_group_exit+0x111/0x300 kernel/exit.c:937
 [<ffffffff8110b0a1>] get_signal+0x4e1/0x1460 kernel/signal.c:2321
 [<ffffffff81051225>] do_signal+0x95/0x1b00 arch/x86/kernel/signal.c:807
 [<ffffffff81003e2e>] exit_to_usermode_loop+0x10e/0x150 arch/x86/entry/common.c:157
 [<ffffffff8100570d>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff8100570d>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff8100570d>] do_syscall_64+0x35d/0x480 arch/x86/entry/common.c:287
 [<ffffffff8278c193>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309abc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309abc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813e68fc>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/1897:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8154c11c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2025:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff8278a262>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff81cdd442>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor4/19192:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81ccd878>] tty_release+0xa88/0xd00 drivers/tty/tty_io.c:1933
1 lock held by init/19553:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2125
1 lock held by init/19554:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2125
1 lock held by init/19555:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2125
1 lock held by init/19556:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2125
1 lock held by init/19557:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2125
1 lock held by init/19560:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81cd1c76>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2125
1 lock held by syz-executor4/19566:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81ceaa67>] ptmx_open+0xf7/0x310 drivers/tty/pty.c:753
1 lock held by syz-executor4/19570:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81ceaa67>] ptmx_open+0xf7/0x310 drivers/tty/pty.c:753
1 lock held by syz-executor2/19590:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81ceaa67>] ptmx_open+0xf7/0x310 drivers/tty/pty.c:753
1 lock held by syz-executor2/19606:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81ceaa67>] ptmx_open+0xf7/0x310 drivers/tty/pty.c:753

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.125+ #89
 ffff8801d9907d08 ffffffff81af0ae9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810967d0 ffff8801d9907d40
 ffffffff81afb849 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81af0ae9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81af0ae9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81afb849>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81afb7dc>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810968d4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8130a04d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8130a04d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8130a04d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8130a04d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff8113d9ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8278c35c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12794 Comm: syz-executor5 Not tainted 4.9.125+ #89
task: ffff8801d2e50000 task.stack: ffff8801a7fb0000
RIP: 0010:[<ffffffff811f7ef7>] 
c [<ffffffff811f7ef7>] trace_hardirqs_off_caller+0x87/0x280 kernel/locking/lockdep.c:2756
RSP: 0018:ffff8801a7fb7ec8  EFLAGS: 00000002
RAX: 0000000000000007 RBX: ffff8801d2e50000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff810055c6 RDI: ffff8801d2e508ac
RBP: ffff8801a7fb7ee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d2e50000
R13: ffffffff810055db R14: ffff8801d2e50000 R15: 0000000000000000
FS:  00007fefbc89e700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff7992f4000 CR3: 00000001d3ba4000 CR4: 00000000001606b0
Stack:
 ffff8801a7fb7f58
c ffff8801d2e50000
c ffff8801a7fb7fd0
c ffff8801a7fb7ef0
c
 ffffffff811f80fd
c ffff8801a7fb7f48
c ffffffff810055db
c 0000000000000000
c
 0000000000000000
c 0000000000000000
c 0000000000000000
c 0000000000000000
c
Call Trace:
 [<ffffffff811f80fd>] trace_hardirqs_off+0xd/0x10 kernel/locking/lockdep.c:2781
 [<ffffffff810055db>] syscall_return_slowpath arch/x86/entry/common.c:259 [inline]
 [<ffffffff810055db>] do_syscall_64+0x22b/0x480 arch/x86/entry/common.c:287
 [<ffffffff8278c193>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c00 
c49 
c8d 
cbc 
c24 
cac 
c08 
c00 
c00 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
cfa 
c48 
cc1 
cea 
c03 
c0f 
cb6 
c14 
c02 
c48 
c89 
cf8 
c83 
ce0 
c07 
c83 
cc0 
c03 
c38 
cd0 
c7c 
c08 
c<84> 
cd2 
c0f 
c85 
cbb 
c01 
c00 
c00 
c41 
c8b 
cb4 
c24 
cac 
c08 
c00 
c00 
c85 
cf6 
c0f 
c85 
c25 
c