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        Mon, 19 Feb 2018 09:42:02 -0500
Subject: Re: BUG: sleeping function called from invalid context at
 net/core/sock.c:LINE (3)
To: Jon Maloy <jon.maloy@ericsson.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        syzbot <syzbot+749d9d87c294c00ca856@syzkaller.appspotmail.com>,
        Ying Xue <ying.xue@windriver.com>
Cc: Andrei Vagin <avagin@virtuozzo.com>,
        David Miller <davem@davemloft.net>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Florian Westphal <fw@strlen.de>,
        LKML <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>,
        Nicolas Dichtel <nicolas.dichtel@6wind.com>,
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        <tipc-discussion@lists.sourceforge.net>
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From: Kirill Tkhai <ktkhai@virtuozzo.com>
Message-ID: <cdfcb6f4-f2db-b710-1b6d-cf15b022c2d3@virtuozzo.com>
Date: Mon, 19 Feb 2018 17:41:54 +0300
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On 19.02.2018 16:23, Jon Maloy wrote:
> I don't understand this one. tipc_topsrv_stop() can only be trigged from a user doing rmmod(), and I double checked that this is running in user mode.
> How does the call chain you are reporting occur?
> 

In case of CONFIG_NET_NS=y, pernet_operations::exit() is called after last reference
to a net is dropped. So, this may happen not only on module unload path.

Kirill

> 
> 
>> -----Original Message-----
>> From: Kirill Tkhai [mailto:ktkhai@virtuozzo.com]
>> Sent: Saturday, February 17, 2018 23:23
>> To: Dmitry Vyukov <dvyukov@google.com>; syzbot
>> <syzbot+749d9d87c294c00ca856@syzkaller.appspotmail.com>; Jon Maloy
>> <jon.maloy@ericsson.com>; Ying Xue <ying.xue@windriver.com>
>> Cc: Andrei Vagin <avagin@virtuozzo.com>; David Miller
>> <davem@davemloft.net>; Eric W. Biederman <ebiederm@xmission.com>;
>> Florian Westphal <fw@strlen.de>; LKML <linux-kernel@vger.kernel.org>;
>> netdev <netdev@vger.kernel.org>; Nicolas Dichtel
>> <nicolas.dichtel@6wind.com>; roman.kapl@sysgo.com; syzkaller-
>> bugs@googlegroups.com; tipc-discussion@lists.sourceforge.net
>> Subject: Re: BUG: sleeping function called from invalid context at
>> net/core/sock.c:LINE (3)
>>
>> On 17.02.2018 11:15, Dmitry Vyukov wrote:
>>> On Sat, Feb 17, 2018 at 4:00 AM, syzbot
>>> <syzbot+749d9d87c294c00ca856@syzkaller.appspotmail.com> wrote:
>>>> Hello,
>>>>
>>>> syzbot hit the following crash on net-next commit
>>>> 65bd449c32c2745df61913ab54087e77f9d9b70d (Fri Feb 16 20:26:35 2018
>>>> +0000) Merge branch 'tipc-de-generealize-topology-server'
>>>
>>> +tipc maintainers
>>
>> This looks to be caused by commit 0ef897be12b8
>> "tipc: separate topology server listener socket from subcsriber sockets"
>>
>> Thanks,
>> Kirill