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

goroutine 310175 [running]:
panic({0x11ee280, 0x210cda0})
	GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc007d67078 sp=0xc007d66fb8 pc=0x436a3b
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:260
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc007d670d8 sp=0xc007d67078 pc=0x44e05d
gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0xc0068906c0, 0xc0007aea86?)
	pkg/sentry/kernel/tty.go:54 +0xa1 fp=0xc007d67168 sp=0xc007d670d8 pc=0x9d6041
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x6bdc5a, 0xc00641e180, 0xc00641e190, {0xc0007aea80?, 0xc001f82a80?, 0x0?})
	pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x445 fp=0xc007d67398 sp=0xc007d67168 pc=0xd6e3e5
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc00641e190, 0xc001f82a80?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0xce fp=0xc007d67400 sp=0xc007d67398 pc=0xd7130e
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc00641e190, {0x15f5f58, 0xc001f82a80}, {{0x15f0490, 0xc00493c000}, {0x0, 0x1, 0x200001c0, 0xa0b}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x1f9 fp=0xc007d674b0 sp=0xc007d67400 pc=0xd70bd9
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc00641e180, {0x15f5f58, 0xc001f82a80}, {{0x15f0490, 0xc00493c000}, {0x0, 0x1, 0x200001c0, 0xa0b}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xcd fp=0xc007d67540 sp=0xc007d674b0 pc=0xd6d22d
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0xc00493c000?, {0x15f5f58?, 0xc001f82a80?}, {{0x15f0490, 0xc00493c000}, {0x0, 0x1, 0x200001c0, 0xa0b}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0x65 fp=0xc007d675a0 sp=0xc007d67540 pc=0xd6f265
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc005765c80, {0x15f5f58, 0xc001f82a80}, {{0x15f0490, 0xc00493c000}, {0x0, 0x1, 0x200001c0, 0xa0b}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0xa5 fp=0xc007d67620 sp=0xc007d675a0 pc=0x7738a5
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0xc004afca80?, 0xc005765c80, {{0x15f0490, 0xc00493c000}, {0x0, 0x1, 0x200001c0, 0xa0b}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x8e fp=0xc007d677f0 sp=0xc007d67620 pc=0xb4196e
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc001f82a80, {{0x4}, {0x200001c0}, {0xa0b}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x25a fp=0xc007d67930 sp=0xc007d677f0 pc=0xb4111a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc001f82a80, 0x1, {{0x4}, {0x200001c0}, {0xa0b}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x80b fp=0xc007d67c70 sp=0xc007d67930 pc=0x9cb66b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc001f82a80, 0x85?, {{0x4}, {0x200001c0}, {0xa0b}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x54 fp=0xc007d67cd0 sp=0xc007d67c70 pc=0x9ccc54
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc007d67d78?, 0x9829e6?, {{0x4}, {0x200001c0}, {0xa0b}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x85 fp=0xc007d67d30 sp=0xc007d67cd0 pc=0x9cc845
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc003f0e410?)
	pkg/sentry/kernel/task_syscall.go:257 +0x3ac fp=0xc007d67e28 sp=0xc007d67d30 pc=0x9cc50c
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc005765b80?, 0xc001f82a80)
	pkg/sentry/kernel/task_run.go:265 +0x144a fp=0xc007d67f60 sp=0xc007d67e28 pc=0x9be14a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc001f82a80, 0x2548)
	pkg/sentry/kernel/task_run.go:94 +0x21c fp=0xc007d67fc0 sp=0xc007d67f60 pc=0x9bc65c
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc007d67fe0 sp=0xc007d67fc0 pc=0x9c9aea
runtime.goexit()
	src/runtime/asm_amd64.s:1598 +0x1 fp=0xc007d67fe8 sp=0xc007d67fe0 pc=0x46d401
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0x105