panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x48 pc=0x89dd6c]

goroutine 2038150 [running]:
panic(0x12296c0, 0x1f83c00)
	GOROOT/src/runtime/panic.go:1065 +0x565 fp=0xc02b1d5560 sp=0xc02b1d5498 pc=0x437c65
runtime.panicmem()
	GOROOT/src/runtime/panic.go:212 +0x5b fp=0xc02b1d5580 sp=0xc02b1d5560 pc=0x435cbb
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:734 +0x173 fp=0xc02b1d55b8 sp=0xc02b1d5580 pc=0x44fa93
gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Dentry).releaseKeptDentriesLocked(0xc00f971cb0, 0x15aa460, 0xc02602e000)
	pkg/sentry/fsimpl/kernfs/filesystem.go:356 +0x4c fp=0xc02b1d5698 sp=0xc02b1d55b8 pc=0x89dd6c
gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Filesystem).Release(0xc02711b340, 0x15aa460, 0xc02602e000)
	pkg/sentry/fsimpl/kernfs/filesystem.go:339 +0xa7 fp=0xc02b1d56d0 sp=0xc02b1d5698 pc=0x89dc67
gvisor.dev/gvisor/pkg/sentry/fsimpl/mqfs.(*filesystem).Release(0xc02711b340, 0x15aa460, 0xc02602e000)
	pkg/sentry/fsimpl/mqfs/mqfs.go:128 +0x7b fp=0xc02b1d56f8 sp=0xc02b1d56d0 pc=0x8c6adb
gvisor.dev/gvisor/pkg/sentry/vfs.(*Filesystem).DecRef.func1()
	pkg/sentry/vfs/filesystem.go:88 +0xe4 fp=0xc02b1d5738 sp=0xc02b1d56f8 pc=0x7a1fe4
gvisor.dev/gvisor/pkg/sentry/vfs.(*FilesystemRefs).DecRef(0xc02711b340, 0xc02b1d57c0)
	bazel-out/k8-fastbuild-ST-4c64f0b3d5c7/bin/pkg/sentry/vfs/filesystem_refs.go:152 +0x82 fp=0xc02b1d57b0 sp=0xc02b1d5738 pc=0x77e8e2
gvisor.dev/gvisor/pkg/sentry/vfs.(*Filesystem).DecRef(0xc02711b340, 0x15aa460, 0xc02602e000)
	pkg/sentry/vfs/filesystem.go:83 +0x73 fp=0xc02b1d57f0 sp=0xc02b1d57b0 pc=0x77de13
gvisor.dev/gvisor/pkg/sentry/vfs.(*Mount).destroy(0xc02abf9ec0, 0x15aa460, 0xc02602e000)
	pkg/sentry/vfs/mount.go:637 +0x93 fp=0xc02b1d5840 sp=0xc02b1d57f0 pc=0x785893
gvisor.dev/gvisor/pkg/sentry/vfs.(*Mount).DecRef(0xc02abf9ec0, 0x15aa460, 0xc02602e000)
	pkg/sentry/vfs/mount.go:616 +0xaa fp=0xc02b1d5868 sp=0xc02b1d5840 pc=0x7857ea
gvisor.dev/gvisor/pkg/sentry/vfs.VirtualDentry.DecRef(0xc02abf9ec0, 0xc00f971cb0, 0x15aa460, 0xc02602e000)
	pkg/sentry/vfs/vfs.go:1182 +0x7f fp=0xc02b1d5890 sp=0xc02b1d5868 pc=0x7944bf
gvisor.dev/gvisor/pkg/sentry/vfs.(*VirtualFilesystem).UmountAt(0xc00022f078, 0x15aa460, 0xc02602e000, 0xc02194fe00, 0xc02b1d5ae0, 0xc02b1d5ac4, 0x0, 0x0)
	pkg/sentry/vfs/mount.go:417 +0x5b3 fp=0xc02b1d5a28 sp=0xc02b1d5890 pc=0x7848f3
gvisor.dev/gvisor/pkg/sentry/syscalls/linux/vfs2.Umount2(0xc02602e000, 0x7fbbc3af5580, 0x2, 0x7fbbc3af558b, 0x56294d170bd3, 0xffffffff, 0x7fbbc3af5350, 0x0, 0x0, 0x0, ...)
	pkg/sentry/syscalls/linux/vfs2/mount.go:187 +0x35d fp=0xc02b1d5ba8 sp=0xc02b1d5a28 pc=0xf2de3d
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc02602e000, 0xa6, 0x7fbbc3af5580, 0x2, 0x7fbbc3af558b, 0x56294d170bd3, 0xffffffff, 0x7fbbc3af5350, 0xc000001fa0, 0x13ddd80, ...)
	pkg/sentry/kernel/task_syscall.go:115 +0x1b9 fp=0xc02b1d5c68 sp=0xc02b1d5ba8 pc=0xa66619
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc02602e000, 0xa6, 0x7fbbc3af5580, 0x2, 0x7fbbc3af558b, 0x56294d170bd3, 0xffffffff, 0x7fbbc3af5350, 0xffffffff, 0x7fbbc3af5350)
	pkg/sentry/kernel/task_syscall.go:290 +0x70 fp=0xc02b1d5cf0 sp=0xc02b1d5c68 pc=0xa678f0
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc02602e000, 0xa6, 0x7fbbc3af5580, 0x2, 0x7fbbc3af558b, 0x56294d170bd3, 0xffffffff, 0x7fbbc3af5350, 0x0, 0x0)
	pkg/sentry/kernel/task_syscall.go:237 +0xb4 fp=0xc02b1d5d50 sp=0xc02b1d5cf0 pc=0xa673d4
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc02602e000, 0x2, 0xc02602e000)
	pkg/sentry/kernel/task_syscall.go:204 +0x198 fp=0xc02b1d5e20 sp=0xc02b1d5d50 pc=0xa66cb8
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0x0, 0xc02602e000, 0x157e4a0, 0x0)
	pkg/sentry/kernel/task_run.go:327 +0xe15 fp=0xc02b1d5f60 sp=0xc02b1d5e20 pc=0xa59b75
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc02602e000, 0xcb80)
	pkg/sentry/kernel/task_run.go:100 +0x1e2 fp=0xc02b1d5fd0 sp=0xc02b1d5f60 pc=0xa58602
runtime.goexit()
	src/runtime/asm_amd64.s:1371 +0x1 fp=0xc02b1d5fd8 sp=0xc02b1d5fd0 pc=0x472861
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:380 +0x116