INFO: task syz-executor1:14473 blocked for more than 140 seconds.
      Not tainted 4.9.140+ #68
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D28824 14473   2108 0x80000000
 ffff8801d6a80000 ffff8801d296ee00 ffff8801d296ee00 ffff8801a299af80
 ffff8801db721018 ffff8801d304fb10 ffffffff82807402 ffff8801d304fae8
 ffffffff81206da7 0000000000000000 00ff8801d6a808a8 ffff8801db7218f0
Call Trace:
 [<ffffffff8280892f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828136cc>] rwsem_down_read_failed+0x26c/0x400 kernel/locking/rwsem-xadd.c:260
 [<ffffffff81b75438>] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 [<ffffffff82811492>] __down_read arch/x86/include/asm/rwsem.h:65 [inline]
 [<ffffffff82811492>] down_read+0x52/0xb0 kernel/locking/rwsem.c:24
 [<ffffffff810e6886>] exit_mm kernel/exit.c:480 [inline]
 [<ffffffff810e6886>] do_exit+0x3c6/0x2a50 kernel/exit.c:820
 [<ffffffff810ed3a1>] do_group_exit+0x111/0x300 kernel/exit.c:937
 [<ffffffff810ed5ad>] SYSC_exit_group kernel/exit.c:948 [inline]
 [<ffffffff810ed5ad>] SyS_exit_group+0x1d/0x20 kernel/exit.c:946
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff828176d3>] 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: [<ffffffff8131c0cc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2018:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815792>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81d37362>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor1/14473:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff810e6886>] exit_mm kernel/exit.c:480 [inline]
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff810e6886>] do_exit+0x3c6/0x2a50 kernel/exit.c:820
1 lock held by syz-executor1/14475:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff810e6886>] exit_mm kernel/exit.c:480 [inline]
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff810e6886>] do_exit+0x3c6/0x2a50 kernel/exit.c:820

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.140+ #68
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4df89>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4df1c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810984b4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131c65d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131c65d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131c65d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131c65d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8281789c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 14479 Comm: syz-executor1 Not tainted 4.9.140+ #68
task: ffff8801c57f0000 task.stack: ffff8801a72a0000
RIP: 0010:[<ffffffff81207aa3>] 
c [<ffffffff81207aa3>] __lock_acquire+0x6f3/0x4a10 kernel/locking/lockdep.c:3335
RSP: 0018:ffff8801a72a7900  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801c57f08d8 RCX: 1ffff10038afe11f
RDX: 1ffff10038afe11b RSI: ffff8801c57f08d8 RDI: ffffffff83ce4d00
RBP: ffff8801a72a7ab0 R08: ffff8801c57f08f8 R09: 0000000000000001
R10: ffff8801c57f0000 R11: 0000000000000000 R12: 00000000000004a4
R13: 0000000000000001 R14: 00000000000004a4 R15: c069dba3f096c9f2
FS:  00007fbcbe243700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4fa394b000 CR3: 00000001c7ebd000 CR4: 00000000001606b0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffff8801c57f0000
c dffffc0000000000
c ffff8801a72a7960
c 0000000000000001
c
 ffff8801c57f08b0
c ffffed0038afe115
c ffff8801c57f0000
c dffffc0000000000
c
 ffff8801a72a7990
c ffffffff81206da7
c ffffffff83ce4cd0
c ffff8801c57f08a8
c
Call Trace:
 [<ffffffff8120c8d0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff8280b090>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
 [<ffffffff8280b090>] mutex_lock_nested+0xc0/0x900 kernel/locking/mutex.c:621
 [<ffffffff813d9d87>] perf_mmap+0x4f7/0x1430 kernel/events/core.c:5270
 [<ffffffff814b422c>] mmap_region+0x80c/0xf90 mm/mmap.c:1726
 [<ffffffff814b4eed>] do_mmap+0x53d/0xbb0 mm/mmap.c:1505
 [<ffffffff81469ef8>] do_mmap_pgoff include/linux/mm.h:2032 [inline]
 [<ffffffff81469ef8>] vm_mmap_pgoff+0x168/0x1b0 mm/util.c:329
 [<ffffffff814af56e>] SYSC_mmap_pgoff mm/mmap.c:1555 [inline]
 [<ffffffff814af56e>] SyS_mmap_pgoff+0xfe/0x1b0 mm/mmap.c:1513
 [<ffffffff8105d3e6>] SYSC_mmap arch/x86/kernel/sys_x86_64.c:96 [inline]
 [<ffffffff8105d3e6>] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:87
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff828176d3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c85 
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c41 
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c00 
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cfc 
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cda 
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cc1 
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c03 
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c00 
c<0f> 
c85 
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c00 
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c48 
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c94 
c24 
c80 
c00 
c00 
c00 
c4c 
c89 
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c48 
cb8 
c00 
c00 
c