panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x91d130]

goroutine 22244 [running]:
panic({0x10ec200, 0x1e68c20})
	GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc000c68f90 sp=0xc000c68ed0 pc=0x436c1b
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:260
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc000c68ff0 sp=0xc000c68f90 pc=0x44e23d
gvisor.dev/gvisor/pkg/sentry/kernel.(*ProcessGroup).SendSignal(0x0, 0xc000c69260)
	pkg/sentry/kernel/sessions.go:237 +0x50 fp=0xc000c690e0 sp=0xc000c68ff0 pc=0x91d130
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0xb90, 0xc00057e180, 0xc00057e190, {0xc0034ba000?, 0xc000a41990?, 0x0?})
	pkg/sentry/fsimpl/devpts/line_discipline.go:400 +0x34e fp=0xc000c69308 sp=0xc000c690e0 pc=0xc894ce
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc00057e190, 0xc001b48000?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0x99 fp=0xc000c69370 sp=0xc000c69308 pc=0xc8bd79
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc00057e190, {0x14c8ed8, 0xc000c6c000}, {{0x14c3190, 0xc001b48000}, {0x0, 0x1, 0x200003c0, 0xb90}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x214 fp=0xc000c69450 sp=0xc000c69370 pc=0xc8b734
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc00057e180, {0x14c8ed8?, 0xc000c6c000?}, {{0x14c3190, 0xc001b48000}, {0x0, 0x1, 0x200003c0, 0xb90}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:217 +0xbf fp=0xc000c694d8 sp=0xc000c69450 pc=0xc8863f
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0x0?, {0x14c8ed8?, 0xc000c6c000?}, {{0x14c3190, 0xc001b48000}, {0x0, 0x1, 0x200003c0, 0xb90}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0x5b fp=0xc000c69538 sp=0xc000c694d8 pc=0xc8a0fb
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc0012a0580, {0x14c8ed8, 0xc000c6c000}, {{0x14c3190, 0xc001b48000}, {0x0, 0x1, 0x200003c0, 0xb90}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0x91 fp=0xc000c695b8 sp=0xc000c69538 pc=0x73fa31
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0xffffffff?, 0xc0012a0580, {{0x14c3190, 0xc001b48000}, {0x0, 0x1, 0x200003c0, 0xb90}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x85 fp=0xc000c69778 sp=0xc000c695b8 pc=0xa85c65
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc000c6c000, {{0x3}, {0x200003c0}, {0xb90}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x1c5 fp=0xc000c69880 sp=0xc000c69778 pc=0xa85545
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc000c6c000, 0x1, {{0x3}, {0x200003c0}, {0xb90}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x755 fp=0xc000c69c70 sp=0xc000c69880 pc=0x942635
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc000c6c000, 0x0?, {{0x3}, {0x200003c0}, {0xb90}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x4a fp=0xc000c69cd0 sp=0xc000c69c70 pc=0x94386a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc00003f440?, 0xc000c69e18?, {{0x3}, {0x200003c0}, {0xb90}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x65 fp=0xc000c69d30 sp=0xc000c69cd0 pc=0x943545
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc0026c00b0?)
	pkg/sentry/kernel/task_syscall.go:257 +0x2f0 fp=0xc000c69e28 sp=0xc000c69d30 pc=0x9432b0
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc001b8f100?, 0xc000c6c000)
	pkg/sentry/kernel/task_run.go:265 +0x103e fp=0xc000c69f60 sp=0xc000c69e28 pc=0x9374de
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc000c6c000, 0x35b)
	pkg/sentry/kernel/task_run.go:94 +0x1b8 fp=0xc000c69fc0 sp=0xc000c69f60 pc=0x935e78
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc000c69fe0 sp=0xc000c69fc0 pc=0x940e2a
runtime.goexit()
	src/runtime/asm_amd64.s:1598 +0x1 fp=0xc000c69fe8 sp=0xc000c69fe0 pc=0x46d5e1
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0xef