panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1ae310d]

goroutine 144374 [running]:
panic({0x3192e0, 0x2647430})
	GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc001a42a08 sp=0xc001a42948 pc=0x125eb5b
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:260
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc001a42a68 sp=0xc001a42a08 pc=0x1277a1d
gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0xc007a92c78, 0x1?)
	pkg/sentry/kernel/tty.go:54 +0xcd fp=0xc001a42b58 sp=0xc001a42a68 pc=0x1ae310d
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x12354ea, 0xc00057a000, 0xc00057a010, {0xc000d2b800, 0x778, 0x778})
	pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x416 fp=0xc001a42db0 sp=0xc001a42b58 pc=0x1ffd1d6
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc00057a010, 0xc00818d000?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0x19f fp=0xc001a42e60 sp=0xc001a42db0 pc=0x200153f
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc00057a010, {0x819e98, 0xc007723500}, {{0x814150, 0xc00818d000}, {0x0, 0x1, 0x20001400, 0x778}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x269 fp=0xc001a42f98 sp=0xc001a42e60 pc=0x2000ae9
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc00057a000, {0x819e98, 0xc007723500}, {{0x814150, 0xc00818d000}, {0x0, 0x1, 0x20001400, 0x778}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xc6 fp=0xc001a43030 sp=0xc001a42f98 pc=0x1ffbe06
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0xc000f11a80, {0x819e98, 0xc007723500}, {{0x814150, 0xc00818d000}, {0x0, 0x1, 0x20001400, 0x778}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0xc5 fp=0xc001a430b0 sp=0xc001a43030 pc=0x1ffe8e5
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc000f11a80, {0x819e98, 0xc007723500}, {{0x814150, 0xc00818d000}, {0x0, 0x1, 0x20001400, 0x778}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0x125 fp=0xc001a43180 sp=0xc001a430b0 pc=0x178d985
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0xffffffff?, 0xc000f11a80, {{0x814150, 0xc00818d000}, {0x0, 0x1, 0x20001400, 0x778}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x9d fp=0xc001a43370 sp=0xc001a43180 pc=0x1cdcb9d
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc007723500, {{0x3}, {0x20001400}, {0x778}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x275 fp=0xc001a434d8 sp=0xc001a43370 pc=0x1cdc255
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc007723500, 0x1, {{0x3}, {0x20001400}, {0x778}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x9b9 fp=0xc001a439b8 sp=0xc001a434d8 pc=0x1ad4099
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc007723500, 0x0?, {{0x3}, {0x20001400}, {0x778}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x7d fp=0xc001a43a50 sp=0xc001a439b8 pc=0x1ad5e7d
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc00814f5f0?, 0xc0016312c0?, {{0x3}, {0x20001400}, {0x778}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x8f fp=0xc001a43ac8 sp=0xc001a43a50 pc=0x1ad582f
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc007723500)
	pkg/sentry/kernel/task_syscall.go:257 +0x4c5 fp=0xc001a43bf0 sp=0xc001a43ac8 pc=0x1ad53c5
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc007723500?, 0xc007723500)
	pkg/sentry/kernel/task_run.go:265 +0x1d4b fp=0xc001a43ec8 sp=0xc001a43bf0 pc=0x1abfe0b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc007723500, 0x14f4)
	pkg/sentry/kernel/task_run.go:94 +0x36b fp=0xc001a43fb0 sp=0xc001a43ec8 pc=0x1abd72b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x48 fp=0xc001a43fe0 sp=0xc001a43fb0 pc=0x1ad1ba8
runtime.goexit()
	src/runtime/asm_amd64.s:1598 +0x1 fp=0xc001a43fe8 sp=0xc001a43fe0 pc=0x1297a01
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0x1ad