panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x9d6041] goroutine 1312292 [running]: panic({0x11ee280, 0x210cda0}) GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc001282ed0 sp=0xc001282e10 pc=0x436a3b runtime.panicmem(...) GOROOT/src/runtime/panic.go:260 runtime.sigpanic() GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc001282f30 sp=0xc001282ed0 pc=0x44e05d gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0xc001c9e768, 0xc00d234ace?) pkg/sentry/kernel/tty.go:54 +0xa1 fp=0xc001282fc0 sp=0xc001282f30 pc=0x9d6041 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x6bdc5a, 0xc0002d8180, 0xc0002d8190, {0xc00d234ac8?, 0xc010bf8c20?, 0x0?}) pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x445 fp=0xc0012831f0 sp=0xc001282fc0 pc=0xd6e3e5 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc0002d8190, 0xc0084fca80?) pkg/sentry/fsimpl/devpts/queue.go:219 +0xce fp=0xc001283258 sp=0xc0012831f0 pc=0xd7130e gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc0002d8190, {0x15f5f58, 0xc0084fca80}, {{0x15f06f8, 0xc001c9e9f0}, {0x0, 0x1, 0x0, 0x13}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/queue.go:183 +0x1f9 fp=0xc001283308 sp=0xc001283258 pc=0xd70bd9 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc0002d8180, {0x15f5f58, 0xc0084fca80}, {{0x15f06f8, 0xc001c9e9f0}, {0x0, 0x1, 0x0, 0x13}, {0x0, ...}}) pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xcd fp=0xc001283398 sp=0xc001283308 pc=0xd6d22d gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0xc001c9e9f0?, {0x15f5f58?, 0xc0084fca80?}, {{0x15f06f8, 0xc001c9e9f0}, {0x0, 0x1, 0x0, 0x13}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/master.go:134 +0x65 fp=0xc0012833f8 sp=0xc001283398 pc=0xd6f265 gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc003cf4200, {0x15f5f58, 0xc0084fca80}, {{0x15f06f8, 0xc001c9e9f0}, {0x0, 0x1, 0x0, 0x13}, {0x0, ...}}, ...) pkg/sentry/vfs/file_description.go:674 +0xa5 fp=0xc001283478 sp=0xc0012833f8 pc=0x7738a5 gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Sendfile(0xc0084fca80, {{0x4}, {0x5}, {0x0}, {0x9e}, {0x0}, {0x0}}) pkg/sentry/syscalls/linux/sys_splice.go:409 +0x152e fp=0xc001283930 sp=0xc001283478 pc=0xb5894e gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc0084fca80, 0x28, {{0x4}, {0x5}, {0x0}, {0x9e}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:142 +0x80b fp=0xc001283c70 sp=0xc001283930 pc=0x9cb66b gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc0084fca80, 0x85?, {{0x4}, {0x5}, {0x0}, {0x9e}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:322 +0x54 fp=0xc001283cd0 sp=0xc001283c70 pc=0x9ccc54 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc001283d78?, 0x9829e6?, {{0x4}, {0x5}, {0x0}, {0x9e}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:282 +0x85 fp=0xc001283d30 sp=0xc001283cd0 pc=0x9cc845 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc00a917930?) pkg/sentry/kernel/task_syscall.go:257 +0x3ac fp=0xc001283e28 sp=0xc001283d30 pc=0x9cc50c gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc003cf4180?, 0xc0084fca80) pkg/sentry/kernel/task_run.go:265 +0x144a fp=0xc001283f60 sp=0xc001283e28 pc=0x9be14a gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc0084fca80, 0xaaf7) pkg/sentry/kernel/task_run.go:94 +0x21c fp=0xc001283fc0 sp=0xc001283f60 pc=0x9bc65c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1() pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc001283fe0 sp=0xc001283fc0 pc=0x9c9aea runtime.goexit() src/runtime/asm_amd64.s:1598 +0x1 fp=0xc001283fe8 sp=0xc001283fe0 pc=0x46d401 created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start pkg/sentry/kernel/task_start.go:377 +0x105