Merge release-20200211.0-17-g4075de1 (automated)

5 files changed, 30 insertions, 8 deletions

diff --git a/pkg/sentry/vfs/context.go b/pkg/sentry/vfs/context.go
index d97362b9a..82781e6d3 100755
--- a/pkg/sentry/vfs/context.go
+++ b/pkg/sentry/vfs/context.go
@@ -29,9 +29,10 @@ const (
 	CtxRoot
 )
 
-// MountNamespaceFromContext returns the MountNamespace used by ctx. It does
-// not take a reference on the returned MountNamespace. If ctx is not
-// associated with a MountNamespace, MountNamespaceFromContext returns nil.
+// MountNamespaceFromContext returns the MountNamespace used by ctx. If ctx is
+// not associated with a MountNamespace, MountNamespaceFromContext returns nil.
+//
+// A reference is taken on the returned MountNamespace.
 func MountNamespaceFromContext(ctx context.Context) *MountNamespace {
 	if v := ctx.Value(CtxMountNamespace); v != nil {
 		return v.(*MountNamespace)
diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go
index 1fbb420f9..ad2c9fcf4 100755
--- a/pkg/sentry/vfs/mount.go
+++ b/pkg/sentry/vfs/mount.go
@@ -114,6 +114,7 @@ type MountNamespace struct {
 func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth.Credentials, source, fsTypeName string, opts *GetFilesystemOptions) (*MountNamespace, error) {
 	rft := vfs.getFilesystemType(fsTypeName)
 	if rft == nil {
+		ctx.Warningf("Unknown filesystem: %s", fsTypeName)
 		return nil, syserror.ENODEV
 	}
 	fs, root, err := rft.fsType.GetFilesystem(ctx, vfs, creds, source, *opts)
@@ -231,9 +232,12 @@ func (vfs *VirtualFilesystem) UmountAt(ctx context.Context, creds *auth.Credenti
 		return syserror.EINVAL
 	}
 	vfs.mountMu.Lock()
-	if mntns := MountNamespaceFromContext(ctx); mntns != nil && mntns != vd.mount.ns {
-		vfs.mountMu.Unlock()
-		return syserror.EINVAL
+	if mntns := MountNamespaceFromContext(ctx); mntns != nil {
+		defer mntns.DecRef()
+		if mntns != vd.mount.ns {
+			vfs.mountMu.Unlock()
+			return syserror.EINVAL
+		}
 	}
 
 	// TODO(jamieliu): Linux special-cases umount of the caller's root, which
diff --git a/pkg/sentry/vfs/options.go b/pkg/sentry/vfs/options.go
index fdf8be157..6af7fdac1 100755
--- a/pkg/sentry/vfs/options.go
+++ b/pkg/sentry/vfs/options.go
@@ -61,7 +61,7 @@ type MountOptions struct {
 type OpenOptions struct {
 	// Flags contains access mode and flags as specified for open(2).
 	//
-	// FilesystemImpls is reponsible for implementing the following flags:
+	// FilesystemImpls are responsible for implementing the following flags:
 	// O_RDONLY, O_WRONLY, O_RDWR, O_APPEND, O_CREAT, O_DIRECT, O_DSYNC,
 	// O_EXCL, O_NOATIME, O_NOCTTY, O_NONBLOCK, O_PATH, O_SYNC, O_TMPFILE, and
 	// O_TRUNC. VFS is responsible for handling O_DIRECTORY, O_LARGEFILE, and
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index 9629afee9..51deae313 100755
--- a/pkg/sentry/vfs/vfs.go
+++ b/pkg/sentry/vfs/vfs.go
@@ -393,7 +393,8 @@ func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credential
 					// be executed.
 					return nil, syserror.EACCES
 				}
-				if linux.FileMode(stat.Mode).FileType() != linux.ModeRegular {
+				if t := linux.FileMode(stat.Mode).FileType(); t != linux.ModeRegular {
+					ctx.Infof("%q is not a regular file: %v", pop.Path, t)
 					return nil, syserror.EACCES
 				}
 			}
@@ -743,6 +744,8 @@ func (vfs *VirtualFilesystem) SyncAllFilesystems(ctx context.Context) error {
 // VirtualDentry methods require that a reference is held on the VirtualDentry.
 //
 // VirtualDentry is analogous to Linux's struct path.
+//
+// +stateify savable
 type VirtualDentry struct {
 	mount  *Mount
 	dentry *Dentry
diff --git a/pkg/sentry/vfs/vfs_state_autogen.go b/pkg/sentry/vfs/vfs_state_autogen.go
index ffcd2b90e..3f14d460c 100755
--- a/pkg/sentry/vfs/vfs_state_autogen.go
+++ b/pkg/sentry/vfs/vfs_state_autogen.go
@@ -35,7 +35,21 @@ func (x *epollInterestEntry) load(m state.Map) {
 	m.Load("prev", &x.prev)
 }
 
+func (x *VirtualDentry) beforeSave() {}
+func (x *VirtualDentry) save(m state.Map) {
+	x.beforeSave()
+	m.Save("mount", &x.mount)
+	m.Save("dentry", &x.dentry)
+}
+
+func (x *VirtualDentry) afterLoad() {}
+func (x *VirtualDentry) load(m state.Map) {
+	m.Load("mount", &x.mount)
+	m.Load("dentry", &x.dentry)
+}
+
 func init() {
 	state.Register("pkg/sentry/vfs.epollInterestList", (*epollInterestList)(nil), state.Fns{Save: (*epollInterestList).save, Load: (*epollInterestList).load})
 	state.Register("pkg/sentry/vfs.epollInterestEntry", (*epollInterestEntry)(nil), state.Fns{Save: (*epollInterestEntry).save, Load: (*epollInterestEntry).load})
+	state.Register("pkg/sentry/vfs.VirtualDentry", (*VirtualDentry)(nil), state.Fns{Save: (*VirtualDentry).save, Load: (*VirtualDentry).load})
 }