Re: [Yaffs] Maybe using a YFREED string in yaffs_DeleteSymLi…

And here is the other message that did not come through

---------------- original message -----------------

Hello Charles,

Here is a shorter patch. Setting .alias to "deleted" negates the need
for NULL checks in several places.

Thanks again,

-Chris

--- yaffs2.orig/yaffs_guts.c    2009-11-10 17:40:41.000000000 -0800
+++ yaffs2/yaffs_guts.c 2009-12-02 16:18:50.000000000 -0800
@@ -5236,7 +5236,7 @@
 static int yaffs_DeleteSymLink(yaffs_Object *in)
 {
        YFREE(in->variant.symLinkVariant.alias);
-
+       in->variant.symLinkVariant.alias = yaffs_CloneString(_Y("deleted"));
        return yaffs_DoGenericObjectDeletion(in);
 }

@@ -5974,10 +5974,21 @@
                                                /* Do nothing */
                                                break;
                                        case YAFFS_OBJECT_TYPE_SYMLINK:
-                                               in->variant.symLinkVariant.alias =
-                                                   yaffs_CloneString(oh->alias);
+                                               /* Note there used to be a bug where for
+                                                * deleted symlinks, .alias was copied
+                                                * from after a free.  Therefore, the
+                                                * value of oh->alias must not be
+                                                * depended upon for deleted symlinks.
+                                                */
+                                               if (oh->parentObjectId == YAFFS_OBJECTID_DELETED)
+                                                       in->variant.symLinkVariant.alias =
+                                                               yaffs_CloneString(_Y("deleted"));
+                                               else
+                                                       in->variant.symLinkVariant.alias =
+                                                               yaffs_CloneString(oh->alias);
                                                if (!in->variant.symLinkVariant.alias)
                                                        alloc_failed = 1;
+
                                                break;
                                        }

@@ -6098,8 +6109,18 @@
                yaffs_SetObjectName(in, oh->name);

                if (in->variantType == YAFFS_OBJECT_TYPE_SYMLINK) {
-                       in->variant.symLinkVariant.alias =
-                                                   yaffs_CloneString(oh->alias);
+                       /* Note there used to be a bug where for
+                        * deleted symlinks, .alias was copied
+                        * from after a free.  Therefore, the
+                        * value of oh->alias must not be
+                        * depended upon for deleted symlinks.
+                        */
+                       if (oh->parentObjectId == YAFFS_OBJECTID_DELETED)
+                               in->variant.symLinkVariant.alias =
+                                       yaffs_CloneString(_Y("deleted"));
+                       else
+                               in->variant.symLinkVariant.alias =
+                                       yaffs_CloneString(oh->alias);
                        if (!in->variant.symLinkVariant.alias)
                                alloc_failed = 1; /* Not returned to caller */
                }
@@ -6717,12 +6738,20 @@
                                                /* Do nothing */
                                                break;
                                        case YAFFS_OBJECT_TYPE_SYMLINK:
-                                               if (oh) {
+                                               /* Note there used to be a bug where for
+                                                * deleted symlinks, .alias was copied
+                                                * from after a free.  Therefore, the
+                                                * value of oh->alias must not be
+                                                * depended upon for deleted symlinks.
+                                                */
+                                               if (oh && oh->parentObjectId == YAFFS_OBJECTID_DELETED)
+                                                       in->variant.symLinkVariant.alias =
+                                                               yaffs_CloneString(_Y("deleted"));
+                                               else if (oh)
                                                        in->variant.symLinkVariant.alias =
                                                                yaffs_CloneString(oh->alias);
-                                                       if (!in->variant.symLinkVariant.alias)
-                                                               alloc_failed = 1;
-                                               }
+                                               if (!in->variant.symLinkVariant.alias)
+                                                       alloc_failed = 1;
                                                break;
                                        }