panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x9d6041] goroutine 161 [running]: panic({0x11ee280, 0x210cda0}) GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc0007d6fb0 sp=0xc0007d6ef0 pc=0x436a3b runtime.panicmem(...) GOROOT/src/runtime/panic.go:260 runtime.sigpanic() GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc0007d7010 sp=0xc0007d6fb0 pc=0x44e05d gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0xc0007ba4e0, 0xc000914000?) pkg/sentry/kernel/tty.go:54 +0xa1 fp=0xc0007d70a0 sp=0xc0007d7010 pc=0x9d6041 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x6bdb1a, 0xc000334180, 0xc000334190, {0xc000914000?, 0xc0003f6a80?, 0x0?}) pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x445 fp=0xc0007d72d0 sp=0xc0007d70a0 pc=0xd6e3e5 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc000334190, 0xc0003f6a80?) pkg/sentry/fsimpl/devpts/queue.go:219 +0xce fp=0xc0007d7338 sp=0xc0007d72d0 pc=0xd7130e gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).read(0xc000334190, {0x15f5f58, 0xc0003f6a80}, {{0x15f0490, 0xc00075a000}, {0x0, 0x0, 0x0, 0x0}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/queue.go:140 +0x3c5 fp=0xc0007d7490 sp=0xc0007d7338 pc=0xd70685 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueRead(0xc000334180, {0x15f5f58, 0xc0003f6a80}, {{0x15f0490, 0xc00075a000}, {0x0, 0x0, 0x0, 0x0}, {0x0, ...}}) pkg/sentry/fsimpl/devpts/line_discipline.go:197 +0xcd fp=0xc0007d7520 sp=0xc0007d7490 pc=0xd6cf8d gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*replicaFileDescription).Read(0x0?, {0x15f5f58?, 0xc0003f6a80?}, {{0x15f0490, 0xc00075a000}, {0x0, 0x0, 0x0, 0x0}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/replica.go:142 +0x6c fp=0xc0007d7580 sp=0xc0007d7520 pc=0xd71e2c gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Read(0xc0007ca280, {0x15f5f58, 0xc0003f6a80}, {{0x15f0490, 0xc00075a000}, {0x0, 0x0, 0x0, 0x0}, {0x0, ...}}, ...) pkg/sentry/vfs/file_description.go:643 +0xea fp=0xc0007d7620 sp=0xc0007d7580 pc=0x7734ea gvisor.dev/gvisor/pkg/sentry/syscalls/linux.read(0x15f5f58?, 0xc0007ca280, {{0x15f0490, 0xc00075a000}, {0x0, 0x0, 0x0, 0x0}, {0x0, 0x1}}, ...) pkg/sentry/syscalls/linux/sys_read_write.go:93 +0x8e fp=0xc0007d77f0 sp=0xc0007d7620 pc=0xb3eb4e gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Readv(0xc0003f6a80, {{0x4}, {0x0}, {0x0}, {0x0}, {0xa}, {0x0}}) pkg/sentry/syscalls/linux/sys_read_write.go:87 +0x23e fp=0xc0007d7930 sp=0xc0007d77f0 pc=0xb3e83e gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc0003f6a80, 0x13, {{0x4}, {0x0}, {0x0}, {0x0}, {0xa}, {0x0}}) pkg/sentry/kernel/task_syscall.go:142 +0x80b fp=0xc0007d7c70 sp=0xc0007d7930 pc=0x9cb66b gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc0003f6a80, 0x0?, {{0x4}, {0x0}, {0x0}, {0x0}, {0xa}, {0x0}}) pkg/sentry/kernel/task_syscall.go:322 +0x54 fp=0xc0007d7cd0 sp=0xc0007d7c70 pc=0x9ccc54 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc00037c310?, 0xc0007d7e18?, {{0x4}, {0x0}, {0x0}, {0x0}, {0xa}, {0x0}}) pkg/sentry/kernel/task_syscall.go:282 +0x85 fp=0xc0007d7d30 sp=0xc0007d7cd0 pc=0x9cc845 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc00021ee70?) pkg/sentry/kernel/task_syscall.go:257 +0x3ac fp=0xc0007d7e28 sp=0xc0007d7d30 pc=0x9cc50c gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc0007ca000?, 0xc0003f6a80) pkg/sentry/kernel/task_run.go:265 +0x144a fp=0xc0007d7f60 sp=0xc0007d7e28 pc=0x9be14a gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc0003f6a80, 0x8) pkg/sentry/kernel/task_run.go:94 +0x21c fp=0xc0007d7fc0 sp=0xc0007d7f60 pc=0x9bc65c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1() pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc0007d7fe0 sp=0xc0007d7fc0 pc=0x9c9aea runtime.goexit() src/runtime/asm_amd64.s:1598 +0x1 fp=0xc0007d7fe8 sp=0xc0007d7fe0 pc=0x46d401 created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start pkg/sentry/kernel/task_start.go:377 +0x105