kernel BUG at fs/nfs/namespace.c:108!

[Shahar Klein <shaharklein@yahoo.com>]

Hi  All

I came across this panic due to bad server and I am wondering
why should an nfs client panic when stumbling upon an IS_ROOT dentry
in the point where it tries to cross mount. I mean: should an 'Innocent' client
'pay' for bad server behavior?

Is it unsafe to just clear the path and return error?


--- a/namespace.c       2008-08-03 12:29:21.000000000 +0300
+++ b/namespace.c       2008-08-03 12:30:54.000000000 +0300
@@ -100,7 +100,11 @@

        dprintk("--> nfs_follow_mountpoint()\n");
  
-       BUG_ON(IS_ROOT(dentry));
+       if (IS_ROOT(dentry)) {
+                 err = -EBUSY; // or any reasonable error
+                 goto out_err;
+                                                                                
+       }
        dprintk("%s: enter\n", __FUNCTION__);
        dput(nd->dentry);
        nd->dentry = dget(dentry);