dlm: fix possible use-after-free

The dlm_put_lkb() can free the lkb and its associated ua structure,
so we can't depend on using the ua struct after the put.

Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 4f74154..eb61648 100644 (file)
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -236,12 +236,12 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type)
        spin_unlock(&proc->asts_spin);
 
        if (eol) {
-               spin_lock(&ua->proc->locks_spin);
+               spin_lock(&proc->locks_spin);
                if (!list_empty(&lkb->lkb_ownqueue)) {
                        list_del_init(&lkb->lkb_ownqueue);
                        dlm_put_lkb(lkb);
                }
-               spin_unlock(&ua->proc->locks_spin);
+               spin_unlock(&proc->locks_spin);
        }
  out:
        mutex_unlock(&ls->ls_clear_proc_locks);