------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(depth <= 0)
WARNING: CPU: 0 PID: 4983 at kernel/locking/lockdep.c:3766 __lock_release kernel/locking/lockdep.c:3766 [inline]
WARNING: CPU: 0 PID: 4983 at kernel/locking/lockdep.c:3766 lock_release+0x5de/0xda0 kernel/locking/lockdep.c:4023
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 4983 Comm: syz-executor7 Not tainted 4.15.0-rc1+ #204
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1dc/0x200 kernel/panic.c:547
 report_bug+0x211/0x2d0 lib/bug.c:184
 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:177
 fixup_bug arch/x86/kernel/traps.c:246 [inline]
 do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:930
RIP: 0010:__lock_release kernel/locking/lockdep.c:3766 [inline]
RIP: 0010:lock_release+0x5de/0xda0 kernel/locking/lockdep.c:4023
RSP: 0018:ffff8801d459f740 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: 1ffff1003a8b3eed RCX: ffffffff8159c48e
RDX: 0000000000010000 RSI: ffffc9000306f000 RDI: 0000000000000000
RBP: ffff8801d459f8b0 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8801c1f242c0 R11: fffffbfff0e8926b R12: ffff8801d459f788
R13: ffff8801d459f888 R14: ffff8801ceac0118 R15: ffffffff87489d60
 up_write+0x6b/0x120 kernel/locking/rwsem.c:131
 destroy_unused_super.part.7+0x18/0xd0 fs/super.c:163
 destroy_unused_super fs/super.c:505 [inline]
 alloc_super fs/super.c:258 [inline]
 sget_userns+0x905/0xe20 fs/super.c:503
 sget+0xd2/0x120 fs/super.c:554
 mount_nodev+0x37/0x100 fs/super.c:1157
 devpts_mount+0x2c/0x40 fs/devpts/inode.c:481
 mount_fs+0x66/0x2d0 fs/super.c:1219
 vfs_kern_mount.part.26+0xc6/0x4a0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:2509 [inline]
 do_new_mount fs/namespace.c:2512 [inline]
 do_mount+0xea4/0x2bb0 fs/namespace.c:2841
 SYSC_mount fs/namespace.c:3057 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3034
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007fe7107aec58 EFLAGS: 00000212 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe7107aeaa0 RCX: 00000000004529d9
RDX: 0000000020e3b000 RSI: 00000000200ba000 RDI: 0000000020c20ff8
RBP: 00007fe7107aea90 R08: 0000000020000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b759b
R13: 00007fe7107aebc8 R14: 00000000004b759b R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..