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Message-ID: <9e5b19c7-1f57-5f19-6331-75c2cfc7800f@huawei.com>
Date: Thu, 22 Feb 2024 10:01:06 +0800
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Subject: Re: [PATCH stable] memcg: add refcnt for pcpu stock to avoid UAF
 problem in drain_all_stock()
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To: Michal Hocko <mhocko@suse.com>
CC: <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>, Johannes Weiner
	<hannes@cmpxchg.org>, Roman Gushchin <roman.gushchin@linux.dev>, Shakeel Butt
	<shakeelb@google.com>, Muchun Song <muchun.song@linux.dev>,
	<cgroups@vger.kernel.org>, <linux-mm@kvack.org>, Wang Weiyang
	<wangweiyang2@huawei.com>, Xiu Jianfeng <xiujianfeng@huawei.com>
References: <20240221081801.69764-1-gongruiqi1@huawei.com>
 <ZdW2gMajIw_cUN2-@tiehlicka>
 <5436af7a-26d4-7c04-466a-7163d5a26040@huawei.com>
 <ZdXLgjpUfpwEwAe0@tiehlicka>
From: Gong Ruiqi <gongruiqi1@huawei.com>
In-Reply-To: <ZdXLgjpUfpwEwAe0@tiehlicka>
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On 2024/02/21 18:08, Michal Hocko wrote:
> On Wed 21-02-24 17:50:27, Gong Ruiqi wrote:
>>
>> On 2024/02/21 16:38, Michal Hocko wrote:
>>> On Wed 21-02-24 16:18:01, GONG, Ruiqi wrote:
>>>> commit 1a3e1f40962c445b997151a542314f3c6097f8c3 upstream.
>>>
>>> I think it would be good to mention that this is only a partial backport
>>> and also explain why to do a partial rather than the full one.
>>>
>>
>> Okay. I think to fix this problem we should add refcnt relation between
>> memcg and stock, and since higher versions have achieved this, maybe
>> it's better to use the same code and align with them. So I put a "commit
>> xxx upstream" here, as requested in kernel docs[1]. So yes it's a
>> partial backport as we only need the stock part.
> 
> I think it is sufficient to mention that this is a partial backport to
> minimize the fix to the bare minimum.
> 

Okay. Then I will send a v2 and add a paragraph to mention this.

> [...]