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Subject: Re: general protection fault in tomoyo_socket_sendmsg_permission
To:     Shuah Khan <skhan@linuxfoundation.org>,
        Hillf Danton <hdanton@sina.com>,
        syzbot <syzbot+95ce4b142579611ef0a9@syzkaller.appspotmail.com>
Cc:     linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>,
        Valentina Manea <valentina.manea.m@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        syzkaller-bugs@googlegroups.com
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From:   Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Message-ID: <954bd943-8b55-36c8-9cba-a35a03213b2c@i-love.sakura.ne.jp>
Date:   Fri, 12 Feb 2021 11:22:13 +0900
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On 2021/02/12 10:34, Shuah Khan wrote:
> On 2/10/21 6:14 PM, Tetsuo Handa wrote:
>> (Dropping LSM ML because this is not a TOMOYO's bug.)
>>
>> On 2021/02/11 4:29, Shuah Khan wrote:
>>> This is a good find. I already replied to the thread to send a complete
>>> fix.
>>
>> As I said at https://lkml.kernel.org/r/f8cae6b1-8f84-0e6a-7d9c-fc4aec68f07b@i-love.sakura.ne.jp ,
>> the as-is patch is effectively a complete fix. And applying the as-is patch should help spending
>> syzbot resources for reproducing "general protection fault in tomoyo_socket_sendmsg_permission"
>> with debug printk() patch applied, which in turn will help you in
>>
>>> Right. I would like to get a clear understanding of how this condition
>>> is triggered. I am not saying this isn't a problem. Understanding how
>>> it is triggered helps find the best fix.
>>
>> part. Therefore, I strongly expect you to apply this version now.
>>
> 
> Is there a reproducer for this problem?

There is no reproducer for "general protection fault in tomoyo_socket_sendmsg_permission" problem, but
the race condition is explained at https://lkml.kernel.org/r/676d4518-0faa-9fab-15db-0db8d216d7fb@i-love.sakura.ne.jp .