Changeset 638

Timestamp:

Jul 20, 2015, 6:02:55 PM (9 years ago)

Author:

guerin

Message:

fat32: disallow move into own subdirectory

"mv / home/a" would crash,
"mv home home/sub" would unfortunately succeed.

File:

• soft/giet_vm/giet_fat32/fat32.c (modified) (4 diffs)

soft/giet_vm/giet_fat32/fat32.c

@@ -309 +309 @@
 static unsigned int _get_inode_from_path( char*          pathname,
                                           fat_inode_t**  inode );
+
+//////////////////////////////////////////////////////////////////////////////////
+// The following function checks if node "a" is an ancestor of inode "b".
+// It returns 0 on failure.
+// It returns 1 otherwise.
+//////////////////////////////////////////////////////////////////////////////////
+
+static unsigned int _is_ancestor( fat_inode_t* a,
+                                  fat_inode_t* b);
 
 //////////////////////////////////////////////////////////////////////////////////
@@ -1575 +1584 @@
     }
 }  // end _add_special_directories
+
+
+
+////////////////////////////////////////////////////////////
+static unsigned int _is_ancestor( fat_inode_t* a,
+                                  fat_inode_t* b )
+{
+    while ( b )
+    {
+        if ( a == b )
+            return 1;
+
+        b = b->parent;
+    }
+
+    return 0;
+} // _is_ancestor()
 
 
@@ -3734 +3760 @@
 //  -10 : "cannot update old_parent directory on device"
 //  -11 : "cannot remove to_remove node from FS"
+//  -12 : "cannot move into its own subdirectory"
 /////////////////////////////////////////////////////////////////////////////////
 int _fat_rename( char*  old_path,
@@ -3803 +3830 @@
         _printf("\n[FAT ERROR] in _fat_rename() : <%s> not found\n", new_path );
         return -3;
+    }
+
+    // check for move into own subdirectory
+    if ( _is_ancestor( old, new_parent ) )
+    {
+        _spin_lock_release( &_fat.fat_lock );
+        _printf("\n[FAT ERROR] in _fat_rename() : can't move %s into its own subdirectory\n", old_path );
+        return -12;
     }