INFO: task syz-executor.2:31866 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #22
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28808 31866   1870 0x80000000
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x22a/0x3c0 kernel/locking/rwsem-xadd.c:309
 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:66 [inline]
 down_read+0x45/0xa0 kernel/locking/rwsem.c:26
 exit_mm kernel/exit.c:511 [inline]
 do_exit+0x575/0x2a20 kernel/exit.c:861
INFO: task syz-executor.2:31868 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #22
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28920 31868   1870 0x80000000
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x22a/0x3c0 kernel/locking/rwsem-xadd.c:309
 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:66 [inline]
 down_read+0x45/0xa0 kernel/locking/rwsem.c:26
 exit_mm kernel/exit.c:511 [inline]
 do_exit+0x575/0x2a20 kernel/exit.c:861

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<00000000e4a76c84>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
1 lock held by rsyslogd/1662:
 #0:  (&f->f_pos_lock){+.+.}, at: [<00000000c04d21ef>] __fdget_pos+0xb5/0xd0 fs/file.c:769
2 locks held by getty/1789:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000779c833f>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000de2a7412>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.2/31866:
 #0:  (&mm->mmap_sem){++++}, at: [<000000005c4257c4>] exit_mm kernel/exit.c:511 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<000000005c4257c4>] do_exit+0x575/0x2a20 kernel/exit.c:861
1 lock held by syz-executor.2/31868:
 #0:  (&mm->mmap_sem){++++}, at: [<000000005c4257c4>] exit_mm kernel/exit.c:511 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<000000005c4257c4>] do_exit+0x575/0x2a20 kernel/exit.c:861

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

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.134+ #22
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xca/0x134 lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 31887 Comm: syz-executor.2 Not tainted 4.14.134+ #22
task: 00000000c6e6a6ff task.stack: 000000002b759d54
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:2358 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:2377 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:2431 [inline]
RIP: 0010:__lock_acquire+0xc86/0x42e0 kernel/locking/lockdep.c:3487
RSP: 0018:ffff88818fc0f890 EFLAGS: 00000086
RAX: 1ffffffff4673c45 RBX: ffffffffa3384660 RCX: 1ffff110334376ef
RDX: 1ffffffff472553e RSI: ffff88819a1bb730 RDI: ffffffffa3384678
RBP: ffff88818fc0fa58 R08: 000000000000281a R09: 0000000000000001
R10: ffff88819a1bb758 R11: c3fc7a2088a96200 R12: dffffc0000000000
R13: c3fc7a2088a96200 R14: ffff88819a1baf00 R15: 0000000000000000
FS:  00007fdc70182700(0000) GS:ffff8881dba00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fef17b9d000 CR3: 00000001c196a002 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
Code: f8 48 c1 e8 03 42 80 3c 20 00 0f 85 4a 21 00 00 48 8b 5b 08 48 85 db 0f 84 b6 04 00 00 48 83 eb 08 0f 84 ac 04 00 00 48 8d 7b 18 <48> 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 9b 20 00 00 4c 3b 6b