panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x99ed1a] goroutine 179 [running]: panic({0x11ef240, 0x210de40}) GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc000a3d310 sp=0xc000a3d250 pc=0x436a3b runtime.panicmem(...) GOROOT/src/runtime/panic.go:260 runtime.sigpanic() GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc000a3d370 sp=0xc000a3d310 pc=0x44e05d gvisor.dev/gvisor/pkg/sentry/kernel.(*ProcessGroup).SendSignal(0x0, 0xc000a3d5e0) pkg/sentry/kernel/sessions.go:237 +0x5a fp=0xc000a3d460 sp=0xc000a3d370 pc=0x99ed1a gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0xc000a3d6f0, 0xc000338180, 0xc000338190, {0xc0005ce000?, 0xc000a3d718?, 0xc000a3d744?}) pkg/sentry/fsimpl/devpts/line_discipline.go:400 +0x445 fp=0xc000a3d690 sp=0xc000a3d460 pc=0xd6e1c5 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc000338190, 0x15ea010?) pkg/sentry/fsimpl/devpts/queue.go:219 +0xce fp=0xc000a3d6f8 sp=0xc000a3d690 pc=0xd7104e gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).setTermios(0xc000338180, 0x4?, {{0x4}, {0x5402}, {0x0}, {0x0}, {0x0}, {0x0}}) pkg/sentry/fsimpl/devpts/line_discipline.go:150 +0x1a5 fp=0xc000a3d798 sp=0xc000a3d6f8 pc=0xd6c6a5 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Ioctl(0xc000672180, {0x15f6fd8, 0xc000b0aa80}, {0x15f1510, 0xc0009b4000}, {{0x4}, {0x5402}, {0x0}, {0x0}, {0x0}, ...}) pkg/sentry/fsimpl/devpts/master.go:156 +0x17a fp=0xc000a3d830 sp=0xc000a3d798 pc=0xd6f1fa gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Ioctl(...) pkg/sentry/vfs/file_description.go:707 gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Ioctl(0xc000b0aa80, {{0x4}, {0x5402}, {0x0}, {0x0}, {0x0}, {0x0}}) pkg/sentry/syscalls/linux/sys_file.go:286 +0x503 fp=0xc000a3d930 sp=0xc000a3d830 pc=0xb224c3 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc000b0aa80, 0x10, {{0x4}, {0x5402}, {0x0}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:142 +0x80b fp=0xc000a3dc70 sp=0xc000a3d930 pc=0x9cb66b gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc000b0aa80, 0x85?, {{0x4}, {0x5402}, {0x0}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:322 +0x54 fp=0xc000a3dcd0 sp=0xc000a3dc70 pc=0x9ccc54 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0x8415cf?, 0x0?, {{0x4}, {0x5402}, {0x0}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:282 +0x85 fp=0xc000a3dd30 sp=0xc000a3dcd0 pc=0x9cc845 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc000566b60?) pkg/sentry/kernel/task_syscall.go:257 +0x3ac fp=0xc000a3de28 sp=0xc000a3dd30 pc=0x9cc50c gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc000540100?, 0xc000b0aa80) pkg/sentry/kernel/task_run.go:265 +0x144a fp=0xc000a3df60 sp=0xc000a3de28 pc=0x9be14a gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc000b0aa80, 0xb) pkg/sentry/kernel/task_run.go:94 +0x21c fp=0xc000a3dfc0 sp=0xc000a3df60 pc=0x9bc65c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1() pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc000a3dfe0 sp=0xc000a3dfc0 pc=0x9c9aea runtime.goexit() src/runtime/asm_amd64.s:1598 +0x1 fp=0xc000a3dfe8 sp=0xc000a3dfe0 pc=0x46d401 created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start pkg/sentry/kernel/task_start.go:377 +0x105