syzbot

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xfe74d3]

goroutine 1092 gp=0xc000455500 m=19 mp=0xc000b01508 [running]:
panic({0x1c598a0?, 0x2c2cca0?})
	bazel-out/k8-fastbuild/bin/external/io_bazel_rules_go/stdlib_/src/runtime/panic.go:804 +0x168 fp=0xc000e46d60 sp=0xc000e46cb0 pc=0x478628
runtime.panicmem(...)
	bazel-out/k8-fastbuild/bin/external/io_bazel_rules_go/stdlib_/src/runtime/panic.go:262
runtime.sigpanic()
	bazel-out/k8-fastbuild/bin/external/io_bazel_rules_go/stdlib_/src/runtime/signal_unix.go:900 +0x359 fp=0xc000e46dc0 sp=0xc000e46d60 pc=0x47adf9
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).SendGroupSignal(0x0, 0xc0009bf480)
	pkg/sentry/kernel/task_signals.go:385 +0x53 fp=0xc000e46e50 sp=0xc000e46dc0 pc=0xfe74d3
gvisor.dev/gvisor/pkg/sentry/kernel.(*rlimitCPUSoftListener).NotifyTimer(0xc00175b3b0, 0xc00175b370?)
	pkg/sentry/kernel/task_acct.go:151 +0xea fp=0xc000e46e80 sp=0xc000e46e50 pc=0xfb2a2a
gvisor.dev/gvisor/pkg/sentry/ktime.(*SyntheticTimer).Set(0xc00175b370, {0x0?, {0x0?}, 0xc0010dd130?}, 0x0)
	pkg/sentry/ktime/synthetic_timer.go:139 +0x342 fp=0xc000e46f58 sp=0xc000e46e80 pc=0xb71562
gvisor.dev/gvisor/pkg/sentry/kernel.(*ThreadGroup).notifyRlimitCPUUpdated(0xc00175ac08, 0x0)
	pkg/sentry/kernel/task_acct.go:103 +0x18a fp=0xc000e47000 sp=0xc000e46f58 pc=0xfb250a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Kernel).NewThreadGroup(0xc0001c7008, 0xc001820a80, 0xc000d45110, 0x0, 0xc000d45120)
	pkg/sentry/kernel/thread_group.go:308 +0x709 fp=0xc000e47078 sp=0xc000e47000 pc=0xffdd49
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Clone(0xc000d9b208, 0xc000e475a0)
	pkg/sentry/kernel/task_clone.go:238 +0x217a fp=0xc000e47580 sp=0xc000e47078 pc=0xfbb5ba
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.clone(0xc000d9b208, 0x24204400, 0x40, 0x0, 0x0, 0x0)
	pkg/sentry/syscalls/linux/sys_thread.go:215 +0x130 fp=0xc000e47670 sp=0xc000e47580 pc=0x12c7050
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Clone(0xc000d9b208, 0x4af8cf?, {{0x24204400}, {0x40}, {0x0}, {0x0}, {0x0}, {0x7ed039b136c0}})
	pkg/sentry/syscalls/linux/sys_clone_amd64.go:36 +0xef fp=0xc000e476e8 sp=0xc000e47670 pc=0x126332f
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc000d9b208, 0x38, {{0x24204400}, {0x40}, {0x0}, {0x0}, {0x0}, {0x7ed039b136c0}})
	pkg/sentry/kernel/task_syscall.go:143 +0xb9f fp=0xc000e47998 sp=0xc000e476e8 pc=0xff463f
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc000d9b208, 0x38, {{0x24204400}, {0x40}, {0x0}, {0x0}, {0x0}, {0x7ed039b136c0}})
	pkg/sentry/kernel/task_syscall.go:323 +0x85 fp=0xc000e47a40 sp=0xc000e47998 pc=0xff6765
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc000d9b208, 0x38, {{0x24204400}, {0x40}, {0x0}, {0x0}, {0x0}, {0x7ed039b136c0}})
	pkg/sentry/kernel/task_syscall.go:283 +0xc7 fp=0xc000e47ab0 sp=0xc000e47a40 pc=0xff6087
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc000d9b208)
	pkg/sentry/kernel/task_syscall.go:258 +0x54a fp=0xc000e47bd0 sp=0xc000e47ab0 pc=0xff5bea
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc000d9b208?, 0xc000d9b208)
	pkg/sentry/kernel/task_run.go:269 +0x2295 fp=0xc000e47e78 sp=0xc000e47bd0 pc=0xfe0675
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc000d9b208, 0x11f)
	pkg/sentry/kernel/task_run.go:97 +0x41b fp=0xc000e47fb0 sp=0xc000e47e78 pc=0xfdd99b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.gowrap1()
	pkg/sentry/kernel/task_start.go:400 +0x45 fp=0xc000e47fe0 sp=0xc000e47fb0 pc=0xff1f45
runtime.goexit({})
	src/runtime/asm_amd64.s:1700 +0x1 fp=0xc000e47fe8 sp=0xc000e47fe0 pc=0x4819a1
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start in goroutine 1021
	pkg/sentry/kernel/task_start.go:400 +0x185