Message-ID: <1448557786.24696.84.camel@edumazet-glaptop2.roam.corp.google.com>
Subject: Re: use-after-free in sock_wake_async
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com>,
        Eric Dumazet <edumazet@google.com>, Dmitry Vyukov <dvyukov@google.com>,
        Benjamin LaHaise <bcrl@kvack.org>,
        "David S. Miller" <davem@davemloft.net>,
        Al Viro <viro@zeniv.linux.org.uk>, David Howells <dhowells@redhat.com>,
        Ying Xue <ying.xue@windriver.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        netdev <netdev@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        syzkaller <syzkaller@googlegroups.com>,
        Kostya Serebryany <kcc@google.com>,
        Alexander Potapenko <glider@google.com>,
        Sasha Levin <sasha.levin@oracle.com>
Date: Thu, 26 Nov 2015 09:09:46 -0800
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On Thu, 2015-11-26 at 18:03 +0100, Hannes Frederic Sowa wrote:

> My rationale was like this: we already have rcu to free the wq, so we
> don't add any more callbacks as current code. sock_alloc is right now
> 1136 bytes, which is huge, like 18 cachelines. I wouldn't think it does
> matter a lot as we thrash anyway. tcp_sock is like 45 cachelines right
> now, hui.

Again, these speculations are really killing me.

Can you wait I send my patches ?

They work just great, and there is no risk of perf regression with added
RCU freeing of inodes :(

It is Thanks Giving in the US, vacation time.

Thanks.


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