panic: WARNING: circular locking detected: kernel.fsContextMutex -> kernfs.filesystemRWMutex: goroutine 527 [running]: gvisor.dev/gvisor/pkg/sync/locking.(*ancestorsAtomicPtrMap).RangeRepeatable(0xc00044ce30, 0xc000c2f8e0) bazel-out/k8-fastbuild/bin/pkg/sync/locking/atomicptrmap_ancestors_unsafe.go:440 +0x1e8 gvisor.dev/gvisor/pkg/sync/locking.checkLock(0xc000292cf0, 0xc00044ce10, {0x0, 0x0, 0x0}) pkg/sync/locking/lockdep.go:112 +0x48a gvisor.dev/gvisor/pkg/sync/locking.AddGLock(0xc000292cf0, 0xffffffffffffffff) pkg/sync/locking/lockdep.go:144 +0x2ec gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*filesystemRWMutex).Lock(0xc00137e1f0) bazel-out/k8-fastbuild/bin/pkg/sentry/fsimpl/kernfs/filesystem_mutex.go:31 +0x3c gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Dentry).DecRef(0xc0006921b0, {0x2112f90, 0xc0007c8588}) pkg/sentry/fsimpl/kernfs/kernfs.go:303 +0xaf gvisor.dev/gvisor/pkg/sentry/vfs.(*Dentry).DecRef(...) pkg/sentry/vfs/dentry.go:156 gvisor.dev/gvisor/pkg/sentry/vfs.VirtualDentry.DecRef({0xc0008240b0?, 0xc0006921b0?}, {0x2112f90, 0xc0007c8588}) pkg/sentry/vfs/vfs.go:1114 +0x6b gvisor.dev/gvisor/pkg/sentry/kernel.(*FSContext).destroy(0xc000642780, {0x2112f90, 0xc0007c8588}) pkg/sentry/kernel/fs_context.go:73 +0x153 gvisor.dev/gvisor/pkg/sentry/kernel.(*runExitMain).execute.(*FSContext).DecRef.func2() pkg/sentry/kernel/fs_context.go:87 +0x47 gvisor.dev/gvisor/pkg/sentry/kernel.(*FSContextRefs).DecRef(0xc000642780, 0xc000c2fda0) bazel-out/k8-fastbuild/bin/pkg/sentry/kernel/fs_context_refs.go:133 +0x6d gvisor.dev/gvisor/pkg/sentry/kernel.(*FSContext).DecRef(...) pkg/sentry/kernel/fs_context.go:86 gvisor.dev/gvisor/pkg/sentry/kernel.(*runExitMain).execute(0xc0007c8588?, 0xc0007c8588) pkg/sentry/kernel/task_exit.go:301 +0x82b gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc0007c8588, 0x44) pkg/sentry/kernel/task_run.go:97 +0x4ca created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start in goroutine 551 pkg/sentry/kernel/task_start.go:416 +0x15c known lock chain: kernfs.filesystemRWMutex -> kernel.taskMutex -> kernel.fsContextMutex ====== kernfs.filesystemRWMutex -> kernel.taskMutex ===== goroutine 111 [running]: gvisor.dev/gvisor/pkg/sentry/kernel.(*taskMutex).Lock(0xc0005d69a0) bazel-out/k8-fastbuild/bin/pkg/sentry/kernel/task_mutex.go:35 +0x3c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).GetNetworkNamespace(0xc0005d6008) pkg/sentry/kernel/task_net.go:48 +0x3c gvisor.dev/gvisor/pkg/sentry/fsimpl/proc.(*filesystem).newTaskNetDir(0xc00019e780, {0x2112f90, 0xc0005d6008}, 0xc0005d6008) pkg/sentry/fsimpl/proc/task_net.go:47 +0x2d3 gvisor.dev/gvisor/pkg/sentry/fsimpl/proc.(*filesystem).newTaskInode(0xc00019e780, {0x2112f90, 0xc0005d6008}, 0xc0005d6008, 0xc0002eef50, 0x1, 0x0) pkg/sentry/fsimpl/proc/task.go:77 +0x15a5 gvisor.dev/gvisor/pkg/sentry/fsimpl/proc.(*tasksInode).Lookup(0xc00002ec08, {0x2112f90, 0xc0005d6008}, {0x1ed2d13, 0x1}) pkg/sentry/fsimpl/proc/tasks.go:147 +0x4aa gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Filesystem).revalidateChildLocked(0xc00019e780, {0x2112f90, 0xc0005d6008}, 0xc0000049e0, 0xc000926e10, {0x1ed2d13, 0x1}) pkg/sentry/fsimpl/kernfs/filesystem.go:127 +0x358 gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Filesystem).stepExistingLocked(0xc00019e780, {0x2112f90, 0xc0005d6008}, 0xc00003a008, 0xc000926e10) pkg/sentry/fsimpl/kernfs/filesystem.go:74 +0x33c gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Filesystem).walkExistingLocked(0xc00019e780, {0x2112f90, 0xc0005d6008}, 0xc00003a008) pkg/sentry/fsimpl/kernfs/filesystem.go:197 +0xc5 gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs.(*Filesystem).ReadlinkAt(0xc00019e780, {0x2112f90, 0xc0005d6008}, 0xc00003a008) pkg/sentry/fsimpl/kernfs/filesystem.go:696 +0x136 gvisor.dev/gvisor/pkg/sentry/vfs.(*VirtualFilesystem).ReadlinkAt(0xc0000049e0, {0x2112f90, 0xc0005d6008}, 0xc0004a0180, 0xc000049588) pkg/sentry/vfs/vfs.go:512 +0xed gvisor.dev/gvisor/pkg/sentry/syscalls/linux.readlinkat(0xc0005d6008, 0xffffff9c, 0xc0000b8070, 0xc0000cad00, 0x80) pkg/sentry/syscalls/linux/sys_file.go:1096 +0x26c gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Readlinkat(0xc0005d6008, 0x4b8c1e?, {{0xffffffffffffff9c}, {0xc0000b8070}, {0xc0000cad00}, {0x80}, {0x0}, {0x0}}) pkg/sentry/syscalls/linux/sys_file.go:1067 +0x46 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc0005d6008, 0x10b, {{0xffffffffffffff9c}, {0xc0000b8070}, {0xc0000cad00}, {0x80}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:143 +0x94c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc0005d6008, 0x10b, {{0xffffffffffffff9c}, {0xc0000b8070}, {0xc0000cad00}, {0x80}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:323 +0x72 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc0005d6008, 0x10b, {{0xffffffffffffff9c}, {0xc0000b8070}, {0xc0000cad00}, {0x80}, {0x0}, {0x0}}) pkg/sentry/kernel/task_syscall.go:283 +0x94 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc0005d6008) pkg/sentry/kernel/task_syscall.go:258 +0x490 gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc0005d6008?, 0xc0005d6008) pkg/sentry/kernel/task_run.go:269 +0x1ec9 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc0005d6008, 0x1) pkg/sentry/kernel/task_run.go:97 +0x4ca created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start in goroutine 1 pkg/sentry/kernel/task_start.go:416 +0x15c ====== kernel.taskMutex -> kernel.fsContextMutex ===== goroutine 287 [running]: gvisor.dev/gvisor/pkg/sentry/kernel.(*fsContextMutex).Lock(0xc0006552c8) bazel-out/k8-fastbuild/bin/pkg/sentry/kernel/fs_context_mutex.go:33 +0x3c gvisor.dev/gvisor/pkg/sentry/kernel.(*FSContext).Fork(0xc0006552c0) pkg/sentry/kernel/fs_context.go:95 +0x53 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Unshare(0xc00080e588, 0x20000) pkg/sentry/kernel/task_clone.go:706 +0x12d2 gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Unshare(0xc00080e588, 0x4b8c1e?, {{0x20000}, {0x7}, {0x7ec410285af0}, {0x0}, {0x0}, {0x561931e386c0}}) pkg/sentry/syscalls/linux/sys_thread.go:453 +0x4f gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc00080e588, 0x110, {{0x20000}, {0x7}, {0x7ec410285af0}, {0x0}, {0x0}, {0x561931e386c0}}) pkg/sentry/kernel/task_syscall.go:143 +0x94c gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc00080e588, 0x110, {{0x20000}, {0x7}, {0x7ec410285af0}, {0x0}, {0x0}, {0x561931e386c0}}) pkg/sentry/kernel/task_syscall.go:323 +0x72 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc00080e588, 0x110, {{0x20000}, {0x7}, {0x7ec410285af0}, {0x0}, {0x0}, {0x561931e386c0}}) pkg/sentry/kernel/task_syscall.go:283 +0x94 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc00080e588) pkg/sentry/kernel/task_syscall.go:258 +0x490 gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc00080e588?, 0xc00080e588) pkg/sentry/kernel/task_run.go:269 +0x1ec9 gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc00080e588, 0x18) pkg/sentry/kernel/task_run.go:97 +0x4ca created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start in goroutine 267 pkg/sentry/kernel/task_start.go:416 +0x15c