Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Subject: Re: [PATCH] mm: fix dereference a null pointer in
 migrate[_huge]_page_move_mapping()
From:   =?UTF-8?B?5p2O5Yqb55C8?= <liqiong@nfschina.com>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
References: <20220217063808.42018-1-liqiong@nfschina.com>
 <Yg35UXjB7RpqVCOI@kroah.com>
 <64157952-22d7-b21b-1b08-c784b8eed1fe@nfschina.com>
Message-ID: <5ee3d92e-99e4-38ce-aee6-66258398f579@nfschina.com>
Date:   Thu, 17 Feb 2022 16:39:33 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.14.0
MIME-Version: 1.0
In-Reply-To: <64157952-22d7-b21b-1b08-c784b8eed1fe@nfschina.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Precedence: bulk

Hi Gerg,

Sorry, i may understand your confusion.
I thought 'Upstream' as the newest code, so, I said 'Upstream has no this bug'.

Yes, we found this bug on 'Upstream v4.19.191'.

How could i submit this patch to 'longterm: 4.19'.

Thanks.

**

在 2022/2/17 下午3:59, 李力琼 写道:
> Hi Greg,
>
> Upstream replaces migrate_page_move_mapping() with 
> folio_migrate_mapping(),
> does not use radix tree any more. So, the upstream don't have the null
> pointer bug.
>
> We found and fix this bug on '4.19.191'.
>
> 在 2022/2/17 下午3:29, Greg KH 写道:
>> On Thu, Feb 17, 2022 at 02:38:08PM +0800, liqiong wrote:
>>> Upstream has no this bug.
>> What do you mean by this?
>>
>> confused,
>>
>> greg k-h