nfsd4: warn on finding lockowner without stateid's

The current code assumes a one-to-one lockowner<->lock stateid
correspondance.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 89e42409b237..9a77a5a21557 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4166,6 +4166,10 @@ static bool same_lockowner_ino(struct nfs4_lockowner *lo, struct inode *inode, c
 
         if (!same_owner_str(&lo->lo_owner, owner, clid))
                 return false;
+        if (list_empty(&lo->lo_owner.so_stateids)) {
+                WARN_ON_ONCE(1);
+                return false;
+        }
         lst = list_first_entry(&lo->lo_owner.so_stateids,
                                struct nfs4_ol_stateid, st_perstateowner);
         return lst->st_file->fi_inode == inode;