INFO: task syz-executor.4:21997 blocked for more than 140 seconds.
      Not tainted 4.14.115+ #64
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28144 21997   1862 0x00000000
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:276 [inline]
 rwsem_down_read_failed+0x21f/0x3c0 kernel/locking/rwsem-xadd.c:293
 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
 i_mmap_lock_read include/linux/fs.h:480 [inline]
 rmap_walk_file+0x2cc/0x3e0 mm/rmap.c:1819
 rmap_walk+0xe5/0x180 mm/rmap.c:1847
 try_to_munlock+0x18e/0x280 mm/rmap.c:1698
 __munlock_isolated_page+0xbf/0x210 mm/mlock.c:132
 __munlock_pagevec+0x493/0x990 mm/mlock.c:340
 munlock_vma_pages_range+0x45b/0x4f0 mm/mlock.c:493
 mlock_fixup+0x3c0/0x490 mm/mlock.c:569
 apply_vma_lock_flags+0x229/0x310 mm/mlock.c:607
 SYSC_munlock mm/mlock.c:738 [inline]
 SyS_munlock+0x7f/0xf0 mm/mlock.c:729
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<00000000a7ef9686>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
2 locks held by getty/1761:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000e6dc6714>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000e3c22048>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.4/21997:
 #0:  (&mm->mmap_sem){++++}, at: [<000000003b9903ed>] SYSC_munlock mm/mlock.c:736 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<000000003b9903ed>] SyS_munlock+0x69/0xf0 mm/mlock.c:729
 #1:  (&mapping->i_mmap_rwsem){++++}, at: [<00000000da189304>] i_mmap_lock_read include/linux/fs.h:480 [inline]
 #1:  (&mapping->i_mmap_rwsem){++++}, at: [<00000000da189304>] rmap_walk_file+0x2cc/0x3e0 mm/rmap.c:1819

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

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.115+ #64
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13270 Comm: syz-executor.3 Not tainted 4.14.115+ #64
task: 00000000e8b8c8f7 task.stack: 00000000d64fb27b
RIP: 0010:do_raw_spin_lock+0xa/0x1c0 kernel/locking/spinlock_debug.c:111
RSP: 0018:ffff88819e477e68 EFLAGS: 00000292
RAX: dffffc0000000000 RBX: ffff8881d0d33c00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8881d3b56630 RDI: ffff8881d0d33cc0
RBP: ffff88819e477f58 R08: 00000000000017d0 R09: 0000000000040094
R10: ffff8881d3b56630 R11: 0000000000000001 R12: fffffffffffffff7
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007fdb43342700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000007 CR3: 00000001d7132002 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 spin_lock include/linux/spinlock.h:317 [inline]
 __alloc_fd+0x3f/0x490 fs/file.c:492
 SYSC_dup fs/file.c:932 [inline]
 SyS_dup+0x32/0xb0 fs/file.c:926
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
Code: 89 0c 24 e8 89 56 32 00 48 8b 74 24 08 4c 8b 0c 24 eb b3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df <41> 55 41 54 55 48 89 fd 48 83 c7 04 48 89 fa 53 48 c1 ea 03 0f