nfsd4: fix null dereference creating nfsv4 callback client
commitb9703d921e254b499b300d652b4f35420176d509
authorJ. Bruce Fields <bfields@citi.umich.edu>
Tue, 15 Sep 2009 16:22:42 +0000 (15 12:22 -0400)
committerGreg Kroah-Hartman <gregkh@suse.de>
Mon, 5 Oct 2009 16:32:12 +0000 (5 09:32 -0700)
tree84db478cafa1aa3a4cfc33fc46ced4eefa8e7437
parent7abf3aa8294d95e3f0be375f30e8d933f874ada0
nfsd4: fix null dereference creating nfsv4 callback client

commit 886e3b7fe6054230c89ae078a09565ed183ecc73 upstream.

On setting up the callback to the client, we attempt to use the same
authentication flavor the client did.  We find an rpc cred to use by
calling rpcauth_lookup_credcache(), which assumes that the given
authentication flavor has a credentials cache.  However, this is not
required to be true--in particular, auth_null does not use one.
Instead, we should call the auth's lookup_cred() method.

Without this, a client attempting to mount using nfsv4 and auth_null
triggers a null dereference.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs/nfsd/nfs4callback.c