------------[ cut here ]------------
WARNING: CPU: 2 PID: 29981 at kernel/futex.c:818 get_pi_state+0x15b/0x190 kernel/futex.c:818
Kernel panic - not syncing: panic_on_warn set ...

CPU: 2 PID: 29981 Comm: syzkaller036041 Not tainted 4.14.0-rc5-next-20171018+ #8
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1c4/0x1e0 kernel/panic.c:546
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:177
 do_trap_no_signal arch/x86/kernel/traps.c:211 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:260
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:297
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:310
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:get_pi_state+0x15b/0x190 kernel/futex.c:818
RSP: 0018:ffff88003b7677a8 EFLAGS: 00010093
RAX: ffff88003be9c340 RBX: 0000000000000000 RCX: ffffffff8162b8db
RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88006b9cbb80
RBP: ffff88003b767838 R08: 0000000000000001 R09: 1ffff100076ecee7
R10: ffff88003b767700 R11: 0000000000000002 R12: 1ffff100076ecef6
R13: ffff88006b9cbb80 R14: 1ffff100076ecefa R15: ffff88006b9cbc30
 exit_pi_state_list+0x556/0x7a0 kernel/futex.c:932
 mm_release+0x46d/0x590 kernel/fork.c:1186
 exit_mm kernel/exit.c:499 [inline]
 do_exit+0x481/0x1ad0 kernel/exit.c:856
 SYSC_exit kernel/exit.c:941 [inline]
 SyS_exit+0x22/0x30 kernel/exit.c:939
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x40393b
RSP: 002b:00007fbca5096d20 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007fbca5097700 RCX: 000000000040393b
RDX: 0000000000000004 RSI: 00000000007fb000 RDI: 0000000000000000
RBP: 0000000000000082 R08: 0000000020048000 R09: 0000000000000000
R10: 000000002000b000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbca50979c0 R15: 00007fbca5097700