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

goroutine 1187247 [running]:
panic({0x10ec220, 0x1e67c20})
	GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc000676ff0 sp=0xc000676f30 pc=0x436c1b
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:260
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc000677050 sp=0xc000676ff0 pc=0x44e23d
gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0x1ec6308?, 0xc00035e912?)
	pkg/sentry/kernel/tty.go:54 +0x9d fp=0xc0006770e0 sp=0xc000677050 pc=0x94b45d
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x47a, 0xc007486300, 0xc007486310, {0xc00035e900?, 0xc00338b0a0?, 0x0?})
	pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x34e fp=0xc000677308 sp=0xc0006770e0 pc=0xc896ae
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc007486310, 0xc001c6d000?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0x99 fp=0xc000677370 sp=0xc000677308 pc=0xc8bf99
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc007486310, {0x14c8e18, 0xc002d3a000}, {{0x14c30d0, 0xc001c6d000}, {0x0, 0x1, 0x200011c0, 0x47a}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x214 fp=0xc000677450 sp=0xc000677370 pc=0xc8b954
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc007486300, {0x14c8e18?, 0xc002d3a000?}, {{0x14c30d0, 0xc001c6d000}, {0x0, 0x1, 0x200011c0, 0x47a}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xbf fp=0xc0006774d8 sp=0xc000677450 pc=0xc8881f
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0x0?, {0x14c8e18?, 0xc002d3a000?}, {{0x14c30d0, 0xc001c6d000}, {0x0, 0x1, 0x200011c0, 0x47a}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0x5b fp=0xc000677538 sp=0xc0006774d8 pc=0xc8a2db
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc00524f580, {0x14c8e18, 0xc002d3a000}, {{0x14c30d0, 0xc001c6d000}, {0x0, 0x1, 0x200011c0, 0x47a}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0x91 fp=0xc0006775b8 sp=0xc000677538 pc=0x73fa31
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0xffffffff?, 0xc00524f580, {{0x14c30d0, 0xc001c6d000}, {0x0, 0x1, 0x200011c0, 0x47a}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x85 fp=0xc000677778 sp=0xc0006775b8 pc=0xa85ee5
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc002d3a000, {{0x3}, {0x200011c0}, {0x47a}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x1c5 fp=0xc000677880 sp=0xc000677778 pc=0xa857c5
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc002d3a000, 0x1, {{0x3}, {0x200011c0}, {0x47a}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x755 fp=0xc000677c70 sp=0xc000677880 pc=0x942635
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc002d3a000, 0x85?, {{0x3}, {0x200011c0}, {0x47a}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x4a fp=0xc000677cd0 sp=0xc000677c70 pc=0x94386a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0x8fa11a?, 0xc00124fe20?, {{0x3}, {0x200011c0}, {0x47a}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x65 fp=0xc000677d30 sp=0xc000677cd0 pc=0x943545
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc005b90820?)
	pkg/sentry/kernel/task_syscall.go:257 +0x2f0 fp=0xc000677e28 sp=0xc000677d30 pc=0x9432b0
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc00294f280?, 0xc002d3a000)
	pkg/sentry/kernel/task_run.go:265 +0x103e fp=0xc000677f60 sp=0xc000677e28 pc=0x9374de
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc002d3a000, 0xcd68)
	pkg/sentry/kernel/task_run.go:94 +0x1b8 fp=0xc000677fc0 sp=0xc000677f60 pc=0x935e78
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc000677fe0 sp=0xc000677fc0 pc=0x940e2a
runtime.goexit()
	src/runtime/asm_amd64.s:1598 +0x1 fp=0xc000677fe8 sp=0xc000677fe0 pc=0x46d5e1
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0xef