From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hangbin Liu <haliu@redhat.com>
Subject: Re: [PATCHv3 iproute2 1/2] lib/libnetlink: re malloc buff if size is
 not enough
Date: Thu, 28 Sep 2017 15:13:06 +0800
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Cc: Hangbin Liu <liuhangbin@gmail.com>,
        Stephen Hemminger <stephen@networkplumber.org>,
        netdev@vger.kernel.org, Phil Sutter <phil@nwl.cc>
To: Michal Kubecek <mkubecek@suse.cz>
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Hi Michal,

On Thu, Sep 21, 2017 at 09:34:20AM +0200, Michal Kubecek wrote:
> I will have to check but IIRC it might be possible to use zero length
> for the peek to only check the length which could help you to avoid both
> the reallocation and copying the same data from kernel to userspace
> twice.

Yes, msg with zero buf length also works. I will post a new patch after fix.

Thanks
Hangbin