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From: Christoph Hellwig <hch@lst.de>
To: Yu Kuai <yukuai1@huaweicloud.com>
Cc: Christoph Hellwig <hch@lst.de>,
	axboe@kernel.dk, willy@infradead.org, kch@nvidia.com,
	martin.petersen@oracle.com, johannes.thumshirn@wdc.com,
	ming.lei@redhat.com, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, yi.zhang@huawei.com,
	"yukuai (C)" <yukuai3@huawei.com>
Subject: Re: [PATCH -nect RFC v2 0/2] block: fix uaf in bd_link_disk_holder()
Date: Sun, 30 Oct 2022 16:30:40 +0100	[thread overview]
Message-ID: <20221030153040.GB9676@lst.de> (raw)
In-Reply-To: <0ad09045-1012-e86b-41f2-a88d02e8f1ed@huaweicloud.com>

On Fri, Oct 21, 2022 at 11:15:34AM +0800, Yu Kuai wrote:
> Hi,
>
> 在 2022/10/21 0:47, Christoph Hellwig 写道:
>> As mentioned before I don't think we should make this even more
>> crufty in the block layer.  See the series I just sent to move it int
>> dm.
>
> It seems we had some misunderstanding, the problem I tried to fix here
> should not just related to dm, but all the caller of
> bd_link_disk_holder().

As far as I can tell the problem was just that patch 1 in my series blows
away the bd_holder_dir pointer in part0 on del_gendisk.  Each holder
actually holds a reference to the kobject, so the memory for it is
still valid, it's just that the pointer got cleared.  I'll send a v2
in a bit.

  parent reply	other threads:[~2022-10-30 15:30 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-20 13:20 [PATCH -nect RFC v2 0/2] block: fix uaf in bd_link_disk_holder() Yu Kuai
2022-10-20 13:20 ` [PATCH -nect RFC v2 1/2] block: add helpers for bd_holder_dir refcount management Yu Kuai
2022-10-20 13:20 ` [PATCH -nect RFC v2 2/2] block: fix uaf for bd_holder_dir Yu Kuai
2022-10-20 16:47 ` [PATCH -nect RFC v2 0/2] block: fix uaf in bd_link_disk_holder() Christoph Hellwig
2022-10-21  3:15   ` Yu Kuai
2022-10-26 11:16     ` Yu Kuai
2022-10-30 15:30     ` Christoph Hellwig [this message]
2022-10-31  1:08       ` Yu Kuai

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