rbd: prevent calling rbdVolume.Destroy() after an error

It seems possible that the .Destroy() function is called on a nil
pointer. This would cause a panic in the node-plugin.

Depending on how far GenVolFromVolID() comes, the returned rbdVolume can
be connected. If an error occurs, the rbdVolume should not be connected
at all, so call the .Destroy() function in those cases too.

Fixes: #4548
Signed-off-by: Niels de Vos <ndevos@ibm.com>

internal/rbd/nodeserver.go

@@ -198,7 +198,6 @@ func (ns *NodeServer) populateRbdVol(
 	} else {
 		rv, err = GenVolFromVolID(ctx, volID, cr, req.GetSecrets())
 		if err != nil {
-			rv.Destroy()
 			log.ErrorLog(ctx, "error generating volume %s: %v", volID, err)
 
 			return nil, status.Errorf(codes.Internal, "error generating volume %s: %v", volID, err)

internal/rbd/rbd_util.go

@@ -1070,6 +1070,8 @@ func updateSnapshotDetails(rbdSnap *rbdSnapshot) error {
 }
 
 // generateVolumeFromVolumeID generates a rbdVolume structure from the provided identifier.
+// The returned rbdVolume is connected in case no error occurred, and should be
+// cleaned up with rbdVolume.Destroy().
 func generateVolumeFromVolumeID(
 	ctx context.Context,
 	volumeID string,
@@ -1116,6 +1118,13 @@ func generateVolumeFromVolumeID(
 	if err != nil {
 		return rbdVol, err
 	}
+	// in case of any error call Destroy for cleanup.
+	defer func() {
+		if err != nil {
+			rbdVol.Destroy()
+		}
+	}()
+
 	rbdVol.JournalPool = rbdVol.Pool
 
 	imageAttributes, err := j.GetImageAttributes(
@@ -1163,6 +1172,8 @@ func generateVolumeFromVolumeID(
 
 // GenVolFromVolID generates a rbdVolume structure from the provided identifier, updating
 // the structure with elements from on-disk image metadata as well.
+// The returned rbdVolume is connected in case no error occurred, and should be
+// cleaned up with rbdVolume.Destroy().
 func GenVolFromVolID(
 	ctx context.Context,
 	volumeID string,
@@ -1185,17 +1196,27 @@ func GenVolFromVolID(
 		!errors.Is(err, ErrImageNotFound) {
 		return vol, err
 	}
+	defer func() {
+		if err != nil {
+			vol.Destroy()
+		}
+	}()
 
 	// Check clusterID mapping exists
-	mapping, mErr := util.GetClusterMappingInfo(vi.ClusterID)
-	if mErr != nil {
-		return vol, mErr
+	mapping, err := util.GetClusterMappingInfo(vi.ClusterID)
+	if err != nil {
+		return vol, err
 	}
 	if mapping != nil {
-		rbdVol, vErr := generateVolumeFromMapping(ctx, mapping, volumeID, vi, cr, secrets)
-		if !errors.Is(vErr, util.ErrKeyNotFound) && !errors.Is(vErr, util.ErrPoolNotFound) &&
-			!errors.Is(vErr, ErrImageNotFound) {
-			return rbdVol, vErr
+		// create a new volume based on the mapping, cleanup the old volume
+		if vol != nil {
+			vol.Destroy()
+		}
+
+		vol, err = generateVolumeFromMapping(ctx, mapping, volumeID, vi, cr, secrets)
+		if !errors.Is(err, util.ErrKeyNotFound) && !errors.Is(err, util.ErrPoolNotFound) &&
+			!errors.Is(err, ErrImageNotFound) {
+			return vol, err
 		}
 	}