panic: Decrementing non-positive ref count 0xc0003ff790, owned by vfs.Filesystem

goroutine 245 [running]:
panic({0xfe2ce0?, 0xc00069a170?})
	GOROOT/src/runtime/panic.go:1017 +0x3ac fp=0xc000799398 sp=0xc0007992e8 pc=0x43a72c
gvisor.dev/gvisor/pkg/sentry/vfs.(*FilesystemRefs).DecRef(0xc0003ff790, 0xc0005df0d0?)
	bazel-out/k8-fastbuild/bin/pkg/sentry/vfs/filesystem_refs.go:126 +0x10c fp=0xc000799400 sp=0xc000799398 pc=0x75580c
gvisor.dev/gvisor/pkg/sentry/vfs.(*Filesystem).DecRef(0xc000799480?, {0x1442c78?, 0xc000456000?})
	pkg/sentry/vfs/filesystem.go:77 +0x4b fp=0xc000799440 sp=0xc000799400 pc=0x75504b
gvisor.dev/gvisor/pkg/sentry/vfs.(*VirtualFilesystem).unlockMounts(0xc0001b7a58, {0x1442c78, 0xc000456000})
	pkg/sentry/vfs/vfs.go:1030 +0x16e fp=0xc0007994f0 sp=0xc000799440 pc=0x7702ae
gvisor.dev/gvisor/pkg/sentry/vfs.(*Mount).destroy.func1()
	pkg/sentry/vfs/mount.go:826 +0x28 fp=0xc000799518 sp=0xc0007994f0 pc=0x75d4e8
gvisor.dev/gvisor/pkg/sentry/vfs.(*Mount).destroy(0xc0002133f0, {0x1442c78, 0xc000456000})
	pkg/sentry/vfs/mount.go:839 +0x1e2 fp=0xc0007995b8 sp=0xc000799518 pc=0x75d442
gvisor.dev/gvisor/pkg/sentry/vfs.(*Mount).DecRef(0xc0002133f0, {0x1442c78, 0xc000456000})
	pkg/sentry/vfs/mount.go:820 +0x65 fp=0xc0007995e0 sp=0xc0007995b8 pc=0x75d225
gvisor.dev/gvisor/pkg/sentry/vfs.(*VirtualFilesystem).unlockMounts(0xc0001b7a58, {0x1442c78, 0xc000456000})
	pkg/sentry/vfs/vfs.go:1030 +0x16e fp=0xc000799690 sp=0xc0007995e0 pc=0x7702ae
gvisor.dev/gvisor/pkg/sentry/vfs.(*VirtualFilesystem).UmountAt.func2()
	pkg/sentry/vfs/mount.go:578 +0x28 fp=0xc0007996b8 sp=0xc000799690 pc=0x75c7e8
gvisor.dev/gvisor/pkg/sentry/vfs.(*VirtualFilesystem).UmountAt(0xc0001b7a58, {0x1442c78, 0xc000456000}, 0xc000805000?, 0xc00057f200?, 0xc00079980c)
	pkg/sentry/vfs/mount.go:602 +0x2fd fp=0xc000799780 sp=0xc0007996b8 pc=0x75c5fd
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Umount2(0xc000456000, 0x0?, {{0x7f2cee838a90}, {0xa}, {0x0}, {0xffffffff}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_mount.go:164 +0x2ab fp=0xc000799918 sp=0xc000799780 pc=0xad346b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc000456000, 0xa6, {{0x7f2cee838a90}, {0xa}, {0x0}, {0xffffffff}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x673 fp=0xc000799c58 sp=0xc000799918 pc=0x992c13
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc000456000, 0xc0006902a8?, {{0x7f2cee838a90}, {0xa}, {0x0}, {0xffffffff}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x45 fp=0xc000799cb8 sp=0xc000799c58 pc=0x993d85
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc000799cf8?, 0x126afd0?, {{0x7f2cee838a90}, {0xa}, {0x0}, {0xffffffff}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x59 fp=0xc000799d18 sp=0xc000799cb8 pc=0x993a99
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc00042e1a0?)
	pkg/sentry/kernel/task_syscall.go:257 +0x2d5 fp=0xc000799e10 sp=0xc000799d18 pc=0x993835
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc000578000?, 0xc000456000)
	pkg/sentry/kernel/task_run.go:269 +0xfb7 fp=0xc000799f48 sp=0xc000799e10 pc=0x987b17
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc000456000, 0x7)
	pkg/sentry/kernel/task_run.go:98 +0x1ef fp=0xc000799fc0 sp=0xc000799f48 pc=0x9864af
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:391 +0x25 fp=0xc000799fe0 sp=0xc000799fc0 pc=0x991525
runtime.goexit()
	src/runtime/asm_amd64.s:1650 +0x1 fp=0xc000799fe8 sp=0xc000799fe0 pc=0x471241
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start in goroutine 131
	pkg/sentry/kernel/task_start.go:391 +0xe5