Re: [B.A.T.M.A.N.] [PATCHv3 maint 5/5] batman-adv: Fix potential synchronization issues in mcast tvlv handler

On Tuesday, June 16, 2015 15:17:23 Linus Lüssing wrote:

•           /* flag checks above + mcast_handler_lock prevents this */
  

•           if (unlikely(!hlist_unhashed(node)))
  

•                   BUG();
  

I don't think this will work because hlist_unhashed() checks for node->pprev being NULL or not. hlist_del_rcu() sets node->pprev to LIST_POISON2.

We could also use BUG_ON() for readability. Something like:

BUG_ON(node->pprev == LIST_POISON2);

Though there are not many code sections working with LIST_POISON2 outside the list handling code.

Cheers, Marek