[PATCH] fuse: check reserved node ID values

This patch checks reserved node ID values returned by lookup and creation
operations.  In case one of the reserved values is sent, return -EIO.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index e79e49b..29f1e9f 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -96,6 +96,8 @@
 	fuse_lookup_init(req, dir, entry, &outarg);
 	request_send(fc, req);
 	err = req->out.h.error;
+	if (!err && (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID))
+		err = -EIO;
 	if (!err) {
 		inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
 				  &outarg.attr);
@@ -152,6 +154,10 @@
 		fuse_put_request(fc, req);
 		return err;
 	}
+	if (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID) {
+		fuse_put_request(fc, req);
+		return -EIO;
+	}
 	inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
 			  &outarg.attr);
 	if (!inode) {