win32_apply.c: Do not request DELETE access on extraction root
authorEric Biggers <ebiggers3@gmail.com>
Wed, 22 May 2013 15:09:47 +0000 (10:09 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Wed, 22 May 2013 15:09:47 +0000 (10:09 -0500)
src/win32_apply.c

index ce20fe6..7148ca8 100644 (file)
@@ -831,9 +831,24 @@ win32_extract_stream(const struct wim_dentry *dentry,
        }
 
        DEBUG("Opening \"%ls\"", stream_path);
        }
 
        DEBUG("Opening \"%ls\"", stream_path);
-       /* DELETE access is needed for SetFileShortNameW(), for some reason. */
-       requestedAccess = GENERIC_READ | GENERIC_WRITE | DELETE |
+       requestedAccess = GENERIC_READ | GENERIC_WRITE |
                          ACCESS_SYSTEM_SECURITY;
                          ACCESS_SYSTEM_SECURITY;
+       /* DELETE access is needed for SetFileShortNameW(), for some reason.
+        * But don't request it for the extraction root, for the following
+        * reasons:
+        *
+        * - Requesting DELETE access on the extraction root will cause a
+        *   sharing violation if the extraction root is the current working
+        *   directory (".").
+        * - The extraction root may be extracted to a different name than given
+        *   in the WIM file, in which case the DOS name, if given, would not be
+        *   meaningful.
+        * - For full-image extractions, the root dentry is supposed to be
+        *   unnamed anyway.
+        * - Microsoft's ImageX does not extract the root directory.
+        */
+       if (dentry != args->extract_root)
+               requestedAccess |= DELETE;
 try_open_again:
        /* Open the stream to be extracted.  Depending on what we have set
         * creationDisposition to, we may be creating this for the first time,
 try_open_again:
        /* Open the stream to be extracted.  Depending on what we have set
         * creationDisposition to, we may be creating this for the first time,