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From: Marek Lindner <mareklindner@neomailbox.ch>
Date: Tue, 16 Jun 2015 22:12 +0800
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Subject: Re: [B.A.T.M.A.N.] [PATCHv3 maint 5/5] batman-adv: Fix potential
	synchronization issues in mcast tvlv handler
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On Tuesday, June 16, 2015 15:17:23 Linus L=FCssing wrote:
> +               /* flag checks above + mcast_handler_lock prevents th=
is */
> +               if (unlikely(!hlist_unhashed(node)))
> +                       BUG();
> +

I don't think this will work because hlist_unhashed() checks for node->=
pprev=20
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 =3D=3D LIST_POISON2);

Though there are not many code sections working with LIST_POISON2 outsi=
de the=20
list handling code.

Cheers,
Marek

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