panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x9d6041] goroutine 721046 [running]: panic({0x11ee280, 0x210cda0}) GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc0010d4fb0 sp=0xc0010d4ef0 pc=0x436a3b runtime.panicmem(...) GOROOT/src/runtime/panic.go:260 runtime.sigpanic() GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc0010d5010 sp=0xc0010d4fb0 pc=0x44e05d gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0xc0064dbc20, 0xc00984730c?) pkg/sentry/kernel/tty.go:54 +0xa1 fp=0xc0010d50a0 sp=0xc0010d5010 pc=0x9d6041 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x6bdb1a, 0xc0017ee000, 0xc0017ee010, {0xc009846000?, 0xc007e92a80?, 0x0?}) pkg/sentry/fsimpl/devpts/line_discipline.go:409 +0x3c6 fp=0xc0010d52d0 sp=0xc0010d50a0 pc=0xd6e366 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc0017ee010, 0xc007e92a80?) pkg/sentry/fsimpl/devpts/queue.go:219 +0xce fp=0xc0010d5338 sp=0xc0010d52d0 pc=0xd7130e gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).read(0xc0017ee010, {0x15f5f58, 0xc007e92a80}, {{0x15f0490, 0xc00ab52000}, {0x0, 0x1, 0x20000340, 0x1000}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/queue.go:140 +0x3c5 fp=0xc0010d5490 sp=0xc0010d5338 pc=0xd70685 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueRead(0xc0017ee000, {0x15f5f58, 0xc007e92a80}, {{0x15f0490, 0xc00ab52000}, {0x0, 0x1, 0x20000340, 0x1000}, {0x0, ...}}) pkg/sentry/fsimpl/devpts/line_discipline.go:197 +0xcd fp=0xc0010d5520 sp=0xc0010d5490 pc=0xd6cf8d gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*replicaFileDescription).Read(0x0?, {0x15f5f58?, 0xc007e92a80?}, {{0x15f0490, 0xc00ab52000}, {0x0, 0x1, 0x20000340, 0x1000}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/replica.go:142 +0x6c fp=0xc0010d5580 sp=0xc0010d5520 pc=0xd71e2c gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Read(0xc00790a000, {0x15f5f58, 0xc007e92a80}, {{0x15f0490, 0xc00ab52000}, {0x0, 0x1, 0x20000340, 0x1000}, {0x0, ...}}, ...) pkg/sentry/vfs/file_description.go:643 +0xea fp=0xc0010d5620 sp=0xc0010d5580 pc=0x7734ea gvisor.dev/gvisor/pkg/sentry/syscalls/linux.read(0xc00690ca80?, 0xc00790a000, {{0x15f0490, 0xc00ab52000}, {0x0, 0x1, 0x20000340, 0x1000}, {0x0, 0x1}}, ...) pkg/sentry/syscalls/linux/sys_read_write.go:93 +0x8e fp=0xc0010d57f0 sp=0xc0010d5620 pc=0xb3eb4e gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Readv(0xc007e92a80, {{0x5}, {0x20000000}, {0x1}, {0x0}, {0x0}, {0x0}}) pkg/sentry/syscalls/linux/sys_read_write.go:87 +0x23e fp=0xc0010d5930 sp=0xc0010d57f0 pc=0xb3e83e gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc007e92a80, 0x13, {{0x5}, {0x20000000}, {0x1}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:142 +0x80b fp=0xc0010d5c70 sp=0xc0010d5930 pc=0x9cb66b gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc007e92a80, 0x85?, {{0x5}, {0x20000000}, {0x1}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:322 +0x54 fp=0xc0010d5cd0 sp=0xc0010d5c70 pc=0x9ccc54 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc0010d5d78?, 0x9829e6?, {{0x5}, {0x20000000}, {0x1}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:282 +0x85 fp=0xc0010d5d30 sp=0xc0010d5cd0 pc=0x9cc845 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc0021000d0?) pkg/sentry/kernel/task_syscall.go:257 +0x3ac fp=0xc0010d5e28 sp=0xc0010d5d30 pc=0x9cc50c gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc003522100?, 0xc007e92a80) pkg/sentry/kernel/task_run.go:265 +0x144a fp=0xc0010d5f60 sp=0xc0010d5e28 pc=0x9be14a gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc007e92a80, 0x4653) pkg/sentry/kernel/task_run.go:94 +0x21c fp=0xc0010d5fc0 sp=0xc0010d5f60 pc=0x9bc65c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1() pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc0010d5fe0 sp=0xc0010d5fc0 pc=0x9c9aea runtime.goexit() src/runtime/asm_amd64.s:1598 +0x1 fp=0xc0010d5fe8 sp=0xc0010d5fe0 pc=0x46d401 created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start pkg/sentry/kernel/task_start.go:377 +0x105