syzbot

panic: WARNING: circular locking detected: kernel.signalHandlersMutex -> kernfs.filesystemRWMutex:
goroutine 211 [running]:
gvisor.dev/gvisor/pkg/sync/locking.(*ancestorsAtomicPtrMap).RangeRepeatable(0xc0000220b0, 0xc00054a808)
	bazel-out/k8-fastbuild-ST-3dcbe13c9b87/bin/pkg/sync/locking/atomicptrmap_ancestors_unsafe.go:441 +0x232
gvisor.dev/gvisor/pkg/sync/locking.checkLock(0xc000360fc0, 0xc000022090, {0x0, 0x0, 0x0})
	pkg/sync/locking/lockdep.go:98 +0x373
gvisor.dev/gvisor/pkg/sync/locking.AddGLock(0xc000360fc0, 0xffffffffffffffff)
	pkg/sync/locking/lockdep.go:126 +0x28c
gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*filesystemRWMutex).Lock(0xc00033e830)
	bazel-out/k8-fastbuild-ST-3dcbe13c9b87/bin/pkg/sentry/fsimpl/kernfs/filesystem_mutex.go:31 +0x45
gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Dentry).DecRef(0xc00056aa20, {0x1b0e328, 0xc00021d0e0})
	pkg/sentry/fsimpl/kernfs/kernfs.go:286 +0x79
gvisor.dev/gvisor/pkg/sentry/kernel.(*Cgroup).decRef(0xc00031a630)
	pkg/sentry/kernel/cgroup.go:121 +0x5c
gvisor.dev/gvisor/pkg/sentry/kernel.(*TaskSet).newTask(0xc000257490, {0x1b0e7f0, 0xc000663500}, 0xc00054b338)
	pkg/sentry/kernel/task_start.go:244 +0x14d1
gvisor.dev/gvisor/pkg/sentry/kernel.(*TaskSet).NewTask(0xc000663500?, {0x1b0e7f0, 0xc000663500}, 0xc00054b338)
	pkg/sentry/kernel/task_start.go:127 +0xeb
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Clone(0xc000663500, 0xc00054b418)
	pkg/sentry/kernel/task_clone.go:219 +0x1da5
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.clone(0x471337?, 0x1200011, 0x0, 0x0, 0x5652dddb55d0, 0x0)
	pkg/sentry/syscalls/linux/sys_thread.go:217 +0xfc
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Clone(0x915a?, {{0x1200011}, {0x0}, {0x0}, {0x5652dddb55d0}, {0x0}, {0x5652dddb5300}})
	pkg/sentry/syscalls/linux/sys_clone_amd64.go:36 +0x4e
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc000663500, 0x38, {{0x1200011}, {0x0}, {0x0}, {0x5652dddb55d0}, {0x0}, {0x5652dddb5300}})
	pkg/sentry/kernel/task_syscall.go:142 +0x9b8
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc000663500, 0x0?, {{0x1200011}, {0x0}, {0x0}, {0x5652dddb55d0}, {0x0}, {0x5652dddb5300}})
	pkg/sentry/kernel/task_syscall.go:322 +0x7d
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc0003c5860?, 0xc0007401e0?, {{0x1200011}, {0x0}, {0x0}, {0x5652dddb55d0}, {0x0}, {0x5652dddb5300}})
	pkg/sentry/kernel/task_syscall.go:282 +0x8f
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc000663500)
	pkg/sentry/kernel/task_syscall.go:257 +0x496
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc000663500?, 0xc000663500)
	pkg/sentry/kernel/task_run.go:253 +0x18f9
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc000663500, 0x12)
	pkg/sentry/kernel/task_run.go:94 +0x354
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:380 +0x1a8