panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x94b45d]

goroutine 2204979 [running]:
panic({0x10ec220, 0x1e67c20})
	GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc001bc8ff0 sp=0xc001bc8f30 pc=0x436c1b
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:260
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc001bc9050 sp=0xc001bc8ff0 pc=0x44e23d
gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0x1ec6308?, 0xc005d51d90?)
	pkg/sentry/kernel/tty.go:54 +0x9d fp=0xc001bc90e0 sp=0xc001bc9050 pc=0x94b45d
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x1, 0xc001654000, 0xc001654010, {0xc005d51d90?, 0xc009ee1360?, 0x0?})
	pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x34e fp=0xc001bc9308 sp=0xc001bc90e0 pc=0xc896ae
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc001654010, 0xc0017a7000?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0x99 fp=0xc001bc9370 sp=0xc001bc9308 pc=0xc8bf99
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc001654010, {0x14c8e18, 0xc008001500}, {{0x14c30d0, 0xc0017a7000}, {0x0, 0x1, 0x20000c80, 0x1}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x214 fp=0xc001bc9450 sp=0xc001bc9370 pc=0xc8b954
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc001654000, {0x14c8e18?, 0xc008001500?}, {{0x14c30d0, 0xc0017a7000}, {0x0, 0x1, 0x20000c80, 0x1}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xbf fp=0xc001bc94d8 sp=0xc001bc9450 pc=0xc8881f
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0x0?, {0x14c8e18?, 0xc008001500?}, {{0x14c30d0, 0xc0017a7000}, {0x0, 0x1, 0x20000c80, 0x1}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0x5b fp=0xc001bc9538 sp=0xc001bc94d8 pc=0xc8a2db
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc0074dcf00, {0x14c8e18, 0xc008001500}, {{0x14c30d0, 0xc0017a7000}, {0x0, 0x1, 0x20000c80, 0x1}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0x91 fp=0xc001bc95b8 sp=0xc001bc9538 pc=0x73fa31
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0xffffffff?, 0xc0074dcf00, {{0x14c30d0, 0xc0017a7000}, {0x0, 0x1, 0x20000c80, 0x1}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x85 fp=0xc001bc9778 sp=0xc001bc95b8 pc=0xa85ee5
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc008001500, {{0x4}, {0x20000c80}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x1c5 fp=0xc001bc9880 sp=0xc001bc9778 pc=0xa857c5
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc008001500, 0x1, {{0x4}, {0x20000c80}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x755 fp=0xc001bc9c70 sp=0xc001bc9880 pc=0x942635
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc008001500, 0x85?, {{0x4}, {0x20000c80}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x4a fp=0xc001bc9cd0 sp=0xc001bc9c70 pc=0x94386a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0x8fa11a?, 0xc0040f6620?, {{0x4}, {0x20000c80}, {0x1}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x65 fp=0xc001bc9d30 sp=0xc001bc9cd0 pc=0x943545
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc00556e0d0?)
	pkg/sentry/kernel/task_syscall.go:257 +0x2f0 fp=0xc001bc9e28 sp=0xc001bc9d30 pc=0x9432b0
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc007da2f80?, 0xc008001500)
	pkg/sentry/kernel/task_run.go:265 +0x103e fp=0xc001bc9f60 sp=0xc001bc9e28 pc=0x9374de
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc008001500, 0xb74)
	pkg/sentry/kernel/task_run.go:94 +0x1b8 fp=0xc001bc9fc0 sp=0xc001bc9f60 pc=0x935e78
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc001bc9fe0 sp=0xc001bc9fc0 pc=0x940e2a
runtime.goexit()
	src/runtime/asm_amd64.s:1598 +0x1 fp=0xc001bc9fe8 sp=0xc001bc9fe0 pc=0x46d5e1
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0xef