panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x9da205]

goroutine 589459 [running]:
panic({0x11e8420, 0x210e530})
	GOROOT/src/runtime/panic.go:1147 +0x3a8 fp=0xc003303380 sp=0xc0033032c0 pc=0x4351c8
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:221
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:735 +0x327 fp=0xc0033033d0 sp=0xc003303380 pc=0x44bd67
gvisor.dev/gvisor/pkg/sentry/kernel.(*ThreadGroup).MigrateCgroup(0x0, {0xc004cf4a20, {0x1556120, 0xc004839500}})
	pkg/sentry/kernel/task_cgroup.go:140 +0x85 fp=0xc0033034a8 sp=0xc0033033d0 pc=0x9da205
gvisor.dev/gvisor/pkg/sentry/fsimpl/cgroupfs.(*cgroupProcsData).Write(0xc0046946f0, {0x156c9d0, 0xc008ed6a80}, 0xc004e93aa0, {{0x1560070, 0xc006b1a7f8}, {0x0, 0x1, 0x0, 0x3}, ...}, ...)
	pkg/sentry/fsimpl/cgroupfs/base.go:305 +0x131 fp=0xc003303510 sp=0xc0033034a8 pc=0xc96411
gvisor.dev/gvisor/pkg/sentry/vfs.(*DynamicBytesFileDescriptionImpl).pwriteLocked(0xc004e93a40, {0x156c9d0, 0xc008ed6a80}, {{0x1560070, 0xc006b1a7f8}, {0x0, 0x1, 0x0, 0x3}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description_impl_util.go:381 +0x2a3 fp=0xc003303630 sp=0xc003303510 pc=0x722683
gvisor.dev/gvisor/pkg/sentry/vfs.(*DynamicBytesFileDescriptionImpl).Write(0xc004e93a40, {0x156c9d0, 0xc008ed6a80}, {{0x1560070, 0xc006b1a7f8}, {0x0, 0x1, 0x0, 0x3}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description_impl_util.go:402 +0xb2 fp=0xc0033036c0 sp=0xc003303630 pc=0x7229b2
gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*DynamicBytesFD).Write(0x0, {0x156c9d0, 0xc008ed6a80}, {{0x1560070, 0xc006b1a7f8}, {0x0, 0x1, 0x0, 0x3}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go:125 +0x65 fp=0xc003303728 sp=0xc0033036c0 pc=0x82de85
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc004e93aa0, {0x156c9d0, 0xc008ed6a80}, {{0x1560070, 0xc006b1a7f8}, {0x0, 0x1, 0x0, 0x3}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:665 +0xa5 fp=0xc0033037a8 sp=0xc003303728 pc=0x71f225
gvisor.dev/gvisor/pkg/sentry/syscalls/linux/vfs2.Sendfile(0xc008ed6a80, {{0x4}, {0x4}, {0x20000000}, {0x3}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/vfs2/splice.go:410 +0x13fa fp=0xc003303bf8 sp=0xc0033037a8 pc=0xf03dba
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc008ed6a80, 0x28, {{0x4}, {0x4}, {0x20000000}, {0x3}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:103 +0x2d7 fp=0xc003303ca8 sp=0xc003303bf8 pc=0x9fae57
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc008ed6a80, 0xc003303d70, {{0x4}, {0x4}, {0x20000000}, {0x3}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:238 +0x57 fp=0xc003303d18 sp=0xc003303ca8 pc=0x9fbc17
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc008633608, 0x8f57310, {{0x4}, {0x4}, {0x20000000}, {0x3}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:198 +0x85 fp=0xc003303d78 sp=0xc003303d18 pc=0x9fb7e5
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc008ed6a80)
	pkg/sentry/kernel/task_syscall.go:173 +0x38e fp=0xc003303e40 sp=0xc003303d78 pc=0x9fb4ae
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc003d6e180, 0xc008ed6a80)
	pkg/sentry/kernel/task_run.go:254 +0x111b fp=0xc003303f60 sp=0xc003303e40 pc=0x9ee59b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc008ed6a80, 0x4b5a)
	pkg/sentry/kernel/task_run.go:95 +0x1ec fp=0xc003303fc0 sp=0xc003303f60 pc=0x9ece0c
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start·dwrap·236()
	pkg/sentry/kernel/task_start.go:339 +0x2a fp=0xc003303fe0 sp=0xc003303fc0 pc=0x9f97ca
runtime.goexit()
	src/runtime/asm_amd64.s:1581 +0x1 fp=0xc003303fe8 sp=0xc003303fe0 pc=0x469321
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:339 +0x106