flags: 0x4000000000004004(referenced|head)
page dumped because: VM_BUG_ON_PAGE(!PageLocked(page))
------------[ cut here ]------------
kernel BUG at mm/filemap.c:817!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 13192 Comm: syz-executor3 Not tainted 4.4.151-g727cfac #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801c77d3000 task.stack: ffff8800bafd8000
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0, id = 0
RIP: 0010:[<ffffffff81421495>]  [<ffffffff81421495>] unlock_page+0x115/0x150 mm/filemap.c:817
RSP: 0018:ffff8800bafdf4b0  EFLAGS: 00010293
RAX: ffffffff83a6f940 RBX: ffffea0002dc8000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81519469 RDI: ffff8801c77d38dc
RBP: ffff8800bafdf4d0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffea0002dc8040 R14: ffffea0002dc8008 R15: ffff8800bafdf598
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000002e320000 CR3: 00000000b3640000 CR4: 00000000001606f0
Stack:
 ffffea0002dc8000 dffffc0000000000 ffffea0002dc8040 ffffea0002dc8008
 ffff8800bafdf5c0 ffffffff812cf2cd ffff8800bafdf688 ffff8800bafdf638
 ffff8801d35b1400 1ffff100175fbea7 00000001c77d38d8 ffff8800bafdf628
Call Trace:
 [<ffffffff812cf2cd>] get_futex_key+0x8ad/0xdc0 kernel/futex.c:598
 [<ffffffff812cf8d5>] futex_wake+0xf5/0x460 kernel/futex.c:1419
 [<ffffffff812d3afd>] do_futex+0x26d/0x17f0 kernel/futex.c:3230
 [<ffffffff812d5270>] SYSC_futex kernel/futex.c:3286 [inline]
 [<ffffffff812d5270>] SyS_futex+0x1f0/0x300 kernel/futex.c:3254
 [<ffffffff8112a541>] mm_release+0x2d1/0x400 kernel/fork.c:953
 [<ffffffff81137c80>] exit_mm kernel/exit.c:395 [inline]
 [<ffffffff81137c80>] do_exit+0x3b0/0x26b0 kernel/exit.c:742
 [<ffffffff8113e1f1>] do_group_exit+0x111/0x330 kernel/exit.c:885
 [<ffffffff811615ec>] get_signal+0x4ec/0x14b0 kernel/signal.c:2321
 [<ffffffff8100df4b>] do_signal+0x8b/0x1d30 arch/x86/kernel/signal.c:712
 [<ffffffff8100360a>] exit_to_usermode_loop+0x11a/0x160 arch/x86/entry/common.c:249
 [<ffffffff8100708e>] prepare_exit_to_usermode arch/x86/entry/common.c:284 [inline]
 [<ffffffff8100708e>] syscall_return_slowpath arch/x86/entry/common.c:349 [inline]
 [<ffffffff8100708e>] do_syscall_32_irqs_on arch/x86/entry/common.c:399 [inline]
 [<ffffffff8100708e>] do_fast_syscall_32+0x61e/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838cdb83>] sysenter_flags_fixed+0xd/0x1a
Code: e8 48 8d 04 c0 49 8d 3c c6 e8 b8 bc df ff 5b 41 5c 41 5d 41 5e 5d c3 e8 7a 31 f3 ff 48 c7 c6 e0 bb a9 83 48 89 df e8 bb ee 06 00 <0f> 0b 48 89 df e8 91 d1 0d 00 e9 0a ff ff ff e8 87 d1 0d 00 e9 
RIP  [<ffffffff81421495>] unlock_page+0x115/0x150 mm/filemap.c:817
 RSP <ffff8800bafdf4b0>
---[ end trace c08654d597fdaddf ]---