panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x4f5264] goroutine 553165 [running]: panic({0xbc4dc0, 0x1939a60}) GOROOT/src/runtime/panic.go:987 +0x3ac fp=0x4004aacf50 sp=0x4004aace90 pc=0x4526c runtime.panicmem() GOROOT/src/runtime/panic.go:260 +0x48 fp=0x4004aacf70 sp=0x4004aacf50 pc=0x43be8 runtime.sigpanic() GOROOT/src/runtime/signal_unix.go:837 +0x214 fp=0x4004aacfb0 sp=0x4004aacf70 pc=0x5c9b4 gvisor.dev/gvisor/pkg/sentry/kernel.(*TTY).SignalForegroundProcessGroup(0x199e1b0?, 0x4000a87518?) pkg/sentry/kernel/tty.go:54 +0xc4 fp=0x4004aad050 sp=0x4004aacfc0 pc=0x4f5264 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x30, 0x40057b2180, 0x40057b2190, {0x4000a87500?, 0x400012fd00?, 0x0?}) pkg/sentry/fsimpl/devpts/line_discipline.go:407 +0x2bc fp=0x4004aad280 sp=0x4004aad050 pc=0x7d773c gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0x40057b2190, 0xfbb6f8?) pkg/sentry/fsimpl/devpts/queue.go:219 +0xb4 fp=0x4004aad2f0 sp=0x4004aad280 pc=0x7d9cc4 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0x40057b2190, {0xfbb6f8, 0x400941aa80}, {{0xfb5d28, 0x4009b8e000}, {0x0, 0x1, 0x20001c80, 0x30}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/queue.go:183 +0x1d8 fp=0x4004aad3d0 sp=0x4004aad2f0 pc=0x7d9658 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0x40057b2180, {0xfbb6f8?, 0x400941aa80?}, {{0xfb5d28, 0x4009b8e000}, {0x0, 0x1, 0x20001c80, 0x30}, {0x0, ...}}) pkg/sentry/fsimpl/devpts/line_discipline.go:220 +0xd4 fp=0x4004aad460 sp=0x4004aad3d0 pc=0x7d69c4 gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0x4004aad4f8?, {0xfbb6f8?, 0x400941aa80?}, {{0xfb5d28, 0x4009b8e000}, {0x0, 0x1, 0x20001c80, 0x30}, {0x0, ...}}, ...) pkg/sentry/fsimpl/devpts/master.go:134 +0x64 fp=0x4004aad4c0 sp=0x4004aad460 pc=0x7d81d4 gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0x4004405e80, {0xfbb6f8, 0x400941aa80}, {{0xfb5d28, 0x4009b8e000}, {0x0, 0x1, 0x20001c80, 0x30}, {0x0, ...}}, ...) pkg/sentry/vfs/file_description.go:674 +0x80 fp=0x4004aad540 sp=0x4004aad4c0 pc=0x3183d0 gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0x0?, 0x4004405e80, {{0xfb5d28, 0x4009b8e000}, {0x0, 0x1, 0x20001c80, 0x30}, {0x0, 0x1}}, ...) pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x88 fp=0x4004aad700 sp=0x4004aad540 pc=0x60e578 gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0x400941aa80, {{0x3}, {0x20001c80}, {0x30}, {0x0}, {0x0}, {0x0}}) pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x134 fp=0x4004aad840 sp=0x4004aad700 pc=0x60df34 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0x400941aa80, 0x40, {{0x3}, {0x20001c80}, {0x30}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:142 +0x5a0 fp=0x4004aadc30 sp=0x4004aad840 pc=0x4ed030 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0x400941aa80, 0x0?, {{0x3}, {0x20001c80}, {0x30}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:322 +0x3c fp=0x4004aadc90 sp=0x4004aadc30 pc=0x4edf2c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0x40012b4de8?, 0x1c62c?, {{0x3}, {0x20001c80}, {0x30}, {0x0}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:282 +0x58 fp=0x4004aadcf0 sp=0x4004aadc90 pc=0x4edc48 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0x40065d7ad0?) pkg/sentry/kernel/task_syscall.go:257 +0x284 fp=0x4004aaddf0 sp=0x4004aadcf0 pc=0x4ed9f4 gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0x4004405d80?, 0x400941aa80) pkg/sentry/kernel/task_run.go:265 +0xdbc fp=0x4004aadf40 sp=0x4004aaddf0 pc=0x4e31dc gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0x400941aa80, 0x6e0d) pkg/sentry/kernel/task_run.go:94 +0x190 fp=0x4004aadfb0 sp=0x4004aadf40 pc=0x4e1e40 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1() pkg/sentry/kernel/task_start.go:377 +0x2c fp=0x4004aadfd0 sp=0x4004aadfb0 pc=0x4ebaec runtime.goexit() src/runtime/asm_arm64.s:1172 +0x4 fp=0x4004aadfd0 sp=0x4004aadfd0 pc=0x7a604 created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start pkg/sentry/kernel/task_start.go:377 +0xe4