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From:   Vladimir Oltean <vladimir.oltean@nxp.com>
To:     Johannes Berg <johannes@sipsolutions.net>
CC:     Yajun Deng <yajun.deng@linux.dev>,
        "davem@davemloft.net" <davem@davemloft.net>,
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        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] net: rtnetlink: Fix rtnl_dereference may be return
 NULL
Thread-Topic: [PATCH v2] net: rtnetlink: Fix rtnl_dereference may be return
 NULL
Thread-Index: AQHXc9vShl7ka6OGCUWvYjkG+ohJDqs406cAgAAYlAA=
Date:   Thu, 8 Jul 2021 11:11:18 +0000
Message-ID: <20210708111118.kti4jprkz7bus62g@skbuf>
References: <20210708092936.20044-1-yajun.deng@linux.dev>
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On Thu, Jul 08, 2021 at 11:43:20AM +0200, Johannes Berg wrote:
> On Thu, 2021-07-08 at 17:29 +0800, Yajun Deng wrote:
> > The value 'link' may be NULL in rtnl_unregister(), this leads to
> > kfree_rcu(NULL, xxx), so add this case handling.
> >
>
> I don't see how. It would require the caller to unregister something
> they never registered. That would be a bug there, but I don't see that
> it's very useful to actually be defensive about bugs there.

Besides, isn't kfree_rcu(NULL) safe anyway?=