INFO: task syz-executor.2:28429 blocked for more than 140 seconds.
      Not tainted 4.9.189+ #20
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28736 28429   2081 0x80000000
 0000000000000083 ffff8801c86917c0 ffff8801d4148000 ffff8801db621000
 ffff8801c733df00 ffff8801db621018 ffff8801d848fba0 ffffffff828176ae
 0000000041b58ab3 ffff8801c86917c0 00ff8801d848faf0 ffff8801db6218f0
Call Trace:
 [<00000000df82ac85>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<00000000e0fa49b9>] rwsem_down_read_failed+0x258/0x3e0 kernel/locking/rwsem-xadd.c:283
 [<000000009467b7a2>] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 [<000000003932bb06>] __down_read arch/x86/include/asm/rwsem.h:65 [inline]
 [<000000003932bb06>] down_read+0x52/0xb0 kernel/locking/rwsem.c:24
 [<00000000e0c5ec88>] exit_mm kernel/exit.c:480 [inline]
 [<00000000e0c5ec88>] do_exit+0x3b7/0x2aa0 kernel/exit.c:828
 [<0000000053005bb0>] do_group_exit+0x111/0x300 kernel/exit.c:945
 [<0000000047e2aaa0>] SYSC_exit_group kernel/exit.c:956 [inline]
 [<0000000047e2aaa0>] SyS_exit_group+0x1d/0x20 kernel/exit.c:954
 [<000000003794ab50>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<00000000b41b43fc>] 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: [<0000000031cc86aa>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
 #0:  (rcu_read_lock){......}, at: [<0000000031cc86aa>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
 #1:  (tasklist_lock){.+.+..}, at: [<0000000014ecd20f>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
2 locks held by getty/2033:
 #0:  (&tty->ldisc_sem){++++++}, at: [<000000005bdacfdd>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<00000000ecd39b4b>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.2/28429:
 #0:  (&mm->mmap_sem){++++++}, at: [<00000000e0c5ec88>] exit_mm kernel/exit.c:480 [inline]
 #0:  (&mm->mmap_sem){++++++}, at: [<00000000e0c5ec88>] do_exit+0x3b7/0x2aa0 kernel/exit.c:828
1 lock held by syz-executor.2/28436:
 #0:  (&mm->mmap_sem){++++++}, at: [<00000000e0c5ec88>] exit_mm kernel/exit.c:480 [inline]
 #0:  (&mm->mmap_sem){++++++}, at: [<00000000e0c5ec88>] do_exit+0x3b7/0x2aa0 kernel/exit.c:828

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.189+ #20
 ffff8801d98d7cc8 ffffffff81b64a91 0000000000000001 0000000000000000
 0000000000000001 ffffffff81099a01 dffffc0000000000 ffff8801d98d7d00
 ffffffff81b6fd2c 0000000000000001 0000000000000000 0000000000000001
Call Trace:
 [<000000005cd85f74>] __dump_stack lib/dump_stack.c:15 [inline]
 [<000000005cd85f74>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<000000007183f431>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
 [<00000000051862b1>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
 [<000000009836f9e5>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<000000004e384a25>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<000000004e384a25>] check_hung_task kernel/hung_task.c:126 [inline]
 [<000000004e384a25>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
 [<000000004e384a25>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
 [<000000005b3e8634>] kthread+0x278/0x310 kernel/kthread.c:211
 [<000000008ffbdb5d>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 28446 Comm: syz-executor.2 Not tainted 4.9.189+ #20
task: 00000000adfb916d task.stack: 00000000e18836a8
RIP: 0010:[<ffffffff8120797e>] 
c [<0000000024a4219d>] lock_is_held+0x3e/0x140 kernel/locking/lockdep.c:3787
RSP: 0018:ffff8801d9e07a98  EFLAGS: 00000202
RAX: 0000000000000007 RBX: ffff8801ca0f17c0 RCX: 1ffffffff063fb70
RDX: 0000000000000000 RSI: 000000000000026c RDI: ffff8801ca0f206c
RBP: ffff8801d9e07ab0 R08: 0000000000000000 R09: ffff8801ca0f2090
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff830d5820
R13: 000000000000026c R14: 0000000000000000 R15: ffff8801ca0ecf60
FS:  00007fe9d848f700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000014fad58 CR3: 00000001d5387000 CR4: 00000000001606b0
Stack:
 0000000000000000
c ffffffff82a51c00
c 000000000000026c
c ffff8801d9e07ae8
c
 ffffffff8116a3ea
c ffff8801ca0f17c0
c ffffffff82a51c00
c 000000000000026c
c
 0000000000000000
c ffff8801ca0ecf60
c ffff8801d9e07b28
c ffffffff8116a535
c
Call Trace:
 [<00000000df5676d0>] ___might_sleep+0x1ca/0x280 kernel/sched/core.c:7970
 [<000000004ea821df>] __might_sleep+0x95/0x1a0 kernel/sched/core.c:7961
 [<0000000060c967dd>] mutex_lock_nested+0x87/0x920 kernel/locking/mutex.c:620
 [<00000000db95eb55>] perf_mmap+0x4d9/0x1580 kernel/events/core.c:5278
 [<00000000ec01e64a>] mmap_region+0x7e7/0xfa0 mm/mmap.c:1726
 [<00000000206edc12>] do_mmap+0x539/0xbc0 mm/mmap.c:1505
 [<00000000f249f2dc>] do_mmap_pgoff include/linux/mm.h:2071 [inline]
 [<00000000f249f2dc>] vm_mmap_pgoff+0x179/0x1c0 mm/util.c:329
 [<00000000e75288cd>] SYSC_mmap_pgoff mm/mmap.c:1555 [inline]
 [<00000000e75288cd>] SyS_mmap_pgoff+0xfa/0x1b0 mm/mmap.c:1513
 [<000000008e3ff629>] SYSC_mmap arch/x86/kernel/sys_x86_64.c:96 [inline]
 [<000000008e3ff629>] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:87
 [<000000003794ab50>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<00000000b41b43fc>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c89 
cfc 
c53 
c65 
c48 
c8b 
c1c 
c25 
c00 
c7e 
c01 
c00 
c48 
c8d 
cbb 
cac 
c08 
c00 
c00 
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 
cd4 
c00 
c00 
c00 
c8b 
c83 
cac 
c08 
c00 
c00 
c85 
cc0 
c0f 
c85 
cb6 
c00 
c00 
c