1 files changed, 48 insertions, 6 deletions

diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index 981e8c7fe..2cee2e6ed 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -424,6 +424,11 @@ type Task struct {
 	// abstractSockets is protected by mu.
 	abstractSockets *AbstractSocketNamespace
 
+	// mountNamespaceVFS2 is the task's mount namespace.
+	//
+	// It is protected by mu. It is owned by the task goroutine.
+	mountNamespaceVFS2 *vfs.MountNamespace
+
 	// parentDeathSignal is sent to this task's thread group when its parent exits.
 	//
 	// parentDeathSignal is protected by mu.
@@ -481,13 +486,10 @@ type Task struct {
 	numaPolicy   int32
 	numaNodeMask uint64
 
-	// If netns is true, the task is in a non-root network namespace. Network
-	// namespaces aren't currently implemented in full; being in a network
-	// namespace simply prevents the task from observing any network devices
-	// (including loopback) or using abstract socket addresses (see unix(7)).
+	// netns is the task's network namespace. netns is never nil.
 	//
-	// netns is protected by mu. netns is owned by the task goroutine.
-	netns bool
+	// netns is protected by mu.
+	netns *inet.Namespace
 
 	// If rseqPreempted is true, before the next call to p.Switch(),
 	// interrupt rseq critical regions as defined by rseqAddr and
@@ -638,6 +640,11 @@ func (t *Task) Value(key interface{}) interface{} {
 		return int32(t.ThreadGroup().ID())
 	case fs.CtxRoot:
 		return t.fsContext.RootDirectory()
+	case vfs.CtxRoot:
+		return t.fsContext.RootDirectoryVFS2()
+	case vfs.CtxMountNamespace:
+		t.mountNamespaceVFS2.IncRef()
+		return t.mountNamespaceVFS2
 	case fs.CtxDirentCacheLimiter:
 		return t.k.DirentCacheLimiter
 	case inet.CtxStack:
@@ -701,6 +708,14 @@ func (t *Task) SyscallRestartBlock() SyscallRestartBlock {
 // Preconditions: The caller must be running on the task goroutine, or t.mu
 // must be locked.
 func (t *Task) IsChrooted() bool {
+	if VFS2Enabled {
+		realRoot := t.mountNamespaceVFS2.Root()
+		defer realRoot.DecRef()
+		root := t.fsContext.RootDirectoryVFS2()
+		defer root.DecRef()
+		return root != realRoot
+	}
+
 	realRoot := t.tg.mounts.Root()
 	defer realRoot.DecRef()
 	root := t.fsContext.RootDirectory()
@@ -774,6 +789,15 @@ func (t *Task) NewFDFrom(fd int32, file *fs.File, flags FDFlags) (int32, error)
 	return fds[0], nil
 }
 
+// NewFDFromVFS2 is a convenience wrapper for t.FDTable().NewFDVFS2.
+//
+// This automatically passes the task as the context.
+//
+// Precondition: same as FDTable.Get.
+func (t *Task) NewFDFromVFS2(fd int32, file *vfs.FileDescription, flags FDFlags) (int32, error) {
+	return t.fdTable.NewFDVFS2(t, fd, file, flags)
+}
+
 // NewFDAt is a convenience wrapper for t.FDTable().NewFDAt.
 //
 // This automatically passes the task as the context.
@@ -783,6 +807,15 @@ func (t *Task) NewFDAt(fd int32, file *fs.File, flags FDFlags) error {
 	return t.fdTable.NewFDAt(t, fd, file, flags)
 }
 
+// NewFDAtVFS2 is a convenience wrapper for t.FDTable().NewFDAtVFS2.
+//
+// This automatically passes the task as the context.
+//
+// Precondition: same as FDTable.
+func (t *Task) NewFDAtVFS2(fd int32, file *vfs.FileDescription, flags FDFlags) error {
+	return t.fdTable.NewFDAtVFS2(t, fd, file, flags)
+}
+
 // WithMuLocked executes f with t.mu locked.
 func (t *Task) WithMuLocked(f func(*Task)) {
 	t.mu.Lock()
@@ -796,6 +829,15 @@ func (t *Task) MountNamespace() *fs.MountNamespace {
 	return t.tg.mounts
 }
 
+// MountNamespaceVFS2 returns t's MountNamespace. A reference is taken on the
+// returned mount namespace.
+func (t *Task) MountNamespaceVFS2() *vfs.MountNamespace {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.mountNamespaceVFS2.IncRef()
+	return t.mountNamespaceVFS2
+}
+
 // AbstractSockets returns t's AbstractSocketNamespace.
 func (t *Task) AbstractSockets() *AbstractSocketNamespace {
 	return t.abstractSockets