panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x4f5264]

goroutine 910791 [running]:
panic({0xbc4dc0, 0x1939a60})
	GOROOT/src/runtime/panic.go:987 +0x3ac fp=0x40019b0f50 sp=0x40019b0e90 pc=0x4526c
runtime.panicmem()
	GOROOT/src/runtime/panic.go:260 +0x48 fp=0x40019b0f70 sp=0x40019b0f50 pc=0x43be8
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x214 fp=0x40019b0fb0 sp=0x40019b0f70 pc=0x5c9b4
gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0x199e1b0?, 0x4007504288?)
	pkg/sentry/kernel/tty.go:54 +0xc4 fp=0x40019b1050 sp=0x40019b0fc0 pc=0x4f5264
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x77, 0x400750c000, 0x400750c010, {0x4007504280?, 0x4004f1c760?, 0x0?})
	pkg/sentry/fsimpl/devpts/line_discipline.go:411 +0x224 fp=0x40019b1280 sp=0x40019b1050 pc=0x7d76a4
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0x400750c010, 0xfbb738?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0xb4 fp=0x40019b12f0 sp=0x40019b1280 pc=0x7d9cc4
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0x400750c010, {0xfbb738, 0x4007076a80}, {{0xfb5d68, 0x40073f4000}, {0x0, 0x1, 0x20000340, 0x77}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x1d8 fp=0x40019b13d0 sp=0x40019b12f0 pc=0x7d9658
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0x400750c000, {0xfbb738?, 0x4007076a80?}, {{0xfb5d68, 0x40073f4000}, {0x0, 0x1, 0x20000340, 0x77}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xd4 fp=0x40019b1460 sp=0x40019b13d0 pc=0x7d69c4
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0x40019b1401?, {0xfbb738?, 0x4007076a80?}, {{0xfb5d68, 0x40073f4000}, {0x0, 0x1, 0x20000340, 0x77}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0x64 fp=0x40019b14c0 sp=0x40019b1460 pc=0x7d81d4
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0x4003edff80, {0xfbb738, 0x4007076a80}, {{0xfb5d68, 0x40073f4000}, {0x0, 0x1, 0x20000340, 0x77}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0x80 fp=0x40019b1540 sp=0x40019b14c0 pc=0x3183d0
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0x4007076a80?, 0x4003edff80, {{0xfb5d68, 0x40073f4000}, {0x0, 0x1, 0x20000340, 0x77}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x88 fp=0x40019b1700 sp=0x40019b1540 pc=0x60e578
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Writev(0x4007076a80, {{0x5}, {0x200003c0}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:341 +0x130 fp=0x40019b1840 sp=0x40019b1700 pc=0x60e2d0
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0x4007076a80, 0x42, {{0x5}, {0x200003c0}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x5a0 fp=0x40019b1c30 sp=0x40019b1840 pc=0x4ed030
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0x4007076a80, 0x0?, {{0x5}, {0x200003c0}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x3c fp=0x40019b1c90 sp=0x40019b1c30 pc=0x4edf2c
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0x40085655e8?, 0x1c62c?, {{0x5}, {0x200003c0}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x58 fp=0x40019b1cf0 sp=0x40019b1c90 pc=0x4edc48
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0x40029729c0?)
	pkg/sentry/kernel/task_syscall.go:257 +0x284 fp=0x40019b1df0 sp=0x40019b1cf0 pc=0x4ed9f4
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0x4003edfe00?, 0x4007076a80)
	pkg/sentry/kernel/task_run.go:265 +0xdbc fp=0x40019b1f40 sp=0x40019b1df0 pc=0x4e31dc
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0x4007076a80, 0xc153)
	pkg/sentry/kernel/task_run.go:94 +0x190 fp=0x40019b1fb0 sp=0x40019b1f40 pc=0x4e1e40
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x2c fp=0x40019b1fd0 sp=0x40019b1fb0 pc=0x4ebaec
runtime.goexit()
	src/runtime/asm_arm64.s:1172 +0x4 fp=0x40019b1fd0 sp=0x40019b1fd0 pc=0x7a604
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0xe4