panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1ae310d] goroutine 1142744 [running]: panic({0x3192e0, 0x2647430}) GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc00818ca08 sp=0xc00818c948 pc=0x125eb5b runtime.panicmem(...) GOROOT/src/runtime/panic.go:260 runtime.sigpanic() GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc00818ca68 sp=0xc00818ca08 pc=0x1277a1d gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0xc00a904240, 0x1?) pkg/sentry/kernel/tty.go:54 +0xcd fp=0xc00818cb58 sp=0xc00818ca68 pc=0x1ae310d gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x12354ea, 0xc0001b2000, 0xc0001b2010, {0xc000546000, 0x63b, 0x63b}) pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x416 fp=0xc00818cdb0 sp=0xc00818cb58 pc=0x1ffd1d6 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc0001b2010, 0xc008c50000?) pkg/sentry/fsimpl/devpts/queue.go:219 +0x19f fp=0xc00818ce60 sp=0xc00818cdb0 pc=0x200153f gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc0001b2010, {0x819e98, 0xc008467500}, {{0x814150, 0xc008c50000}, {0x0, 0x1, 0x20000dc0, 0x63b}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/queue.go:183 +0x269 fp=0xc00818cf98 sp=0xc00818ce60 pc=0x2000ae9 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc0001b2000, {0x819e98, 0xc008467500}, {{0x814150, 0xc008c50000}, {0x0, 0x1, 0x20000dc0, 0x63b}, {0x0, ...}}) pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xc6 fp=0xc00818d030 sp=0xc00818cf98 pc=0x1ffbe06 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0xc007fdc180, {0x819e98, 0xc008467500}, {{0x814150, 0xc008c50000}, {0x0, 0x1, 0x20000dc0, 0x63b}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/master.go:134 +0xc5 fp=0xc00818d0b0 sp=0xc00818d030 pc=0x1ffe8e5 gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc007fdc180, {0x819e98, 0xc008467500}, {{0x814150, 0xc008c50000}, {0x0, 0x1, 0x20000dc0, 0x63b}, {0x0, ...}}, ...) pkg/sentry/vfs/file_description.go:674 +0x125 fp=0xc00818d180 sp=0xc00818d0b0 pc=0x178d985 gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0xffffffff?, 0xc007fdc180, {{0x814150, 0xc008c50000}, {0x0, 0x1, 0x20000dc0, 0x63b}, {0x0, 0x1}}, ...) pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x9d fp=0xc00818d370 sp=0xc00818d180 pc=0x1cdcb9d gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc008467500, {{0x3}, {0x20000dc0}, {0x63b}, {0x0}, {0x0}, {0x0}}) pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x275 fp=0xc00818d4d8 sp=0xc00818d370 pc=0x1cdc255 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc008467500, 0x1, {{0x3}, {0x20000dc0}, {0x63b}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:142 +0x9b9 fp=0xc00818d9b8 sp=0xc00818d4d8 pc=0x1ad4099 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc008467500, 0x0?, {{0x3}, {0x20000dc0}, {0x63b}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:322 +0x7d fp=0xc00818da50 sp=0xc00818d9b8 pc=0x1ad5e7d gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc001db6dd0?, 0xc00340ce10?, {{0x3}, {0x20000dc0}, {0x63b}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:282 +0x8f fp=0xc00818dac8 sp=0xc00818da50 pc=0x1ad582f gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc008467500) pkg/sentry/kernel/task_syscall.go:257 +0x4c5 fp=0xc00818dbf0 sp=0xc00818dac8 pc=0x1ad53c5 gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc008467500?, 0xc008467500) pkg/sentry/kernel/task_run.go:265 +0x1d4b fp=0xc00818dec8 sp=0xc00818dbf0 pc=0x1abfe0b gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc008467500, 0xab57) pkg/sentry/kernel/task_run.go:94 +0x36b fp=0xc00818dfb0 sp=0xc00818dec8 pc=0x1abd72b gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1() pkg/sentry/kernel/task_start.go:377 +0x48 fp=0xc00818dfe0 sp=0xc00818dfb0 pc=0x1ad1ba8 runtime.goexit() src/runtime/asm_amd64.s:1598 +0x1 fp=0xc00818dfe8 sp=0xc00818dfe0 pc=0x1297a01 created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start pkg/sentry/kernel/task_start.go:377 +0x1ad