WARNING: CPU: 1 PID: 22 at fs/namespace.c:1115 cleanup_mnt+0x118/0x160 fs/namespace.c:1115
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.2.0-rc2+ #16
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events proc_cleanup_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2cb/0x744 kernel/panic.c:219
 __warn.cold+0x20/0x4d kernel/panic.c:576
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:cleanup_mnt+0x118/0x160 fs/namespace.c:1115
Code: 1c 01 00 00 48 c7 c7 40 29 c6 88 e8 62 a8 5d 05 48 8d 7b 38 48 c7 c6 f0 4b ba 81 e8 42 5c a4 ff 5b 41 5c 5d c3 e8 c8 46 b6 ff <0f> 0b e9 0e ff ff ff e8 bc 46 b6 ff 48 89 df e8 a4 04 06 00 e9 31
RSP: 0018:ffff8880a9a1fc88 EFLAGS: 00010293
RAX: ffff8880a9a105c0 RBX: ffff888089481000 RCX: ffffffff81ba5e04
RDX: 0000000000000000 RSI: ffffffff81ba5ef8 RDI: 0000000000000005
RBP: ffff8880a9a1fc98 R08: ffff8880a9a105c0 R09: fffffbfff11424e6
R10: fffffbfff11424e5 R11: ffffffff88a1272b R12: 000000000000e268
R13: ffff888089481030 R14: ffff888089481070 R15: ffff888089481078
 mntput_no_expire fs/namespace.c:1199 [inline]
 mntput_no_expire+0x7d4/0x960 fs/namespace.c:1141
 mntput fs/namespace.c:1209 [inline]
 kern_unmount fs/namespace.c:3779 [inline]
 kern_unmount+0xbd/0xf0 fs/namespace.c:3773
 pid_ns_release_proc+0x37/0x41 fs/proc/root.c:336
 proc_cleanup_work+0x19/0x20 kernel/pid_namespace.c:65
 process_one_work+0x989/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x354/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..