panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x9d6041]

goroutine 1308387 [running]:
panic({0x11ee280, 0x210cda0})
	GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc00d749078 sp=0xc00d748fb8 pc=0x436a3b
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:260
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc00d7490d8 sp=0xc00d749078 pc=0x44e05d
gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0xc00198df38, 0xc00a8bc002?)
	pkg/sentry/kernel/tty.go:54 +0xa1 fp=0xc00d749168 sp=0xc00d7490d8 pc=0x9d6041
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x6bdc5a, 0xc000342300, 0xc000342310, {0xc00a8bc000?, 0xc007e3aa80?, 0x0?})
	pkg/sentry/fsimpl/devpts/line_discipline.go:411 +0x34c fp=0xc00d749398 sp=0xc00d749168 pc=0xd6e2ec
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc000342310, 0xc007e3aa80?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0xce fp=0xc00d749400 sp=0xc00d749398 pc=0xd7130e
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc000342310, {0x15f5f58, 0xc007e3aa80}, {{0x15f0490, 0xc007f84000}, {0x0, 0x1, 0x20000280, 0xff2e}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x1f9 fp=0xc00d7494b0 sp=0xc00d749400 pc=0xd70bd9
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc000342300, {0x15f5f58, 0xc007e3aa80}, {{0x15f0490, 0xc007f84000}, {0x0, 0x1, 0x20000280, 0xff2e}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xcd fp=0xc00d749540 sp=0xc00d7494b0 pc=0xd6d22d
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0x0?, {0x15f5f58?, 0xc007e3aa80?}, {{0x15f0490, 0xc007f84000}, {0x0, 0x1, 0x20000280, 0xff2e}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0x65 fp=0xc00d7495a0 sp=0xc00d749540 pc=0xd6f265
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc00605cf80, {0x15f5f58, 0xc007e3aa80}, {{0x15f0490, 0xc007f84000}, {0x0, 0x1, 0x20000280, 0xff2e}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0xa5 fp=0xc00d749620 sp=0xc00d7495a0 pc=0x7738a5
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0xc00cfbc000?, 0xc00605cf80, {{0x15f0490, 0xc007f84000}, {0x0, 0x1, 0x20000280, 0xff2e}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x8e fp=0xc00d7497f0 sp=0xc00d749620 pc=0xb4196e
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc007e3aa80, {{0x4}, {0x20000280}, {0xff2e}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x25a fp=0xc00d749930 sp=0xc00d7497f0 pc=0xb4111a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc007e3aa80, 0x1, {{0x4}, {0x20000280}, {0xff2e}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x80b fp=0xc00d749c70 sp=0xc00d749930 pc=0x9cb66b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc007e3aa80, 0x85?, {{0x4}, {0x20000280}, {0xff2e}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x54 fp=0xc00d749cd0 sp=0xc00d749c70 pc=0x9ccc54
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc00d749d78?, 0x9829e6?, {{0x4}, {0x20000280}, {0xff2e}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x85 fp=0xc00d749d30 sp=0xc00d749cd0 pc=0x9cc845
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc00764fd40?)
	pkg/sentry/kernel/task_syscall.go:257 +0x3ac fp=0xc00d749e28 sp=0xc00d749d30 pc=0x9cc50c
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc007c14080?, 0xc007e3aa80)
	pkg/sentry/kernel/task_run.go:265 +0x144a fp=0xc00d749f60 sp=0xc00d749e28 pc=0x9be14a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc007e3aa80, 0x8055)
	pkg/sentry/kernel/task_run.go:94 +0x21c fp=0xc00d749fc0 sp=0xc00d749f60 pc=0x9bc65c
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc00d749fe0 sp=0xc00d749fc0 pc=0x9c9aea
runtime.goexit()
	src/runtime/asm_amd64.s:1598 +0x1 fp=0xc00d749fe8 sp=0xc00d749fe0 pc=0x46d401
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0x105