From: Christoph Hellwig <hch@infradead.org>
To: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>,
Yufen Yu <yuyufen@huawei.com>,
axboe@kernel.dk, linux-block@vger.kernel.org, tj@kernel.org,
bvanassche@acm.org, tytso@mit.edu, gregkh@linuxfoundation.org
Subject: Re: [PATCH v4 0/6] bdi: fix use-after-free for bdi device
Date: Wed, 15 Apr 2020 22:36:50 -0700 [thread overview]
Message-ID: <20200416053650.GA522@infradead.org> (raw)
In-Reply-To: <20200415093459.GH501@quack2.suse.cz>
On Wed, Apr 15, 2020 at 11:34:59AM +0200, Jan Kara wrote:
> Yeah, that's what I was suggesting as well [1] - especially since we
> already have bdi->name with a dubious value (but looking into it now, we
> would need a separate dev_name field since bdi->name is visible in sysfs so
> we cannot change that).
That is a little anoying, but not the end of the world.
> But Yufen explained to me that this could result in
> bogus name being reported when bdi gets re-registered. Not sure if that's
> serious enough but it could happen...
I don't think that is a problem at all. If it is a problem we can just
replace the ->dev_name pointer with one that says "(unregistered)" at
unregister time, but to me that seems worse than just keeping the name
around.
prev parent reply other threads:[~2020-04-16 5:36 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-25 12:38 [PATCH v4 0/6] bdi: fix use-after-free for bdi device Yufen Yu
2020-03-25 12:38 ` [PATCH v4 1/6] bdi: use bdi_dev_name() to get device name Yufen Yu
2020-03-25 12:38 ` [PATCH v4 2/6] bdi: protect bdi->dev with spinlock Yufen Yu
2020-03-25 12:38 ` [PATCH v4 3/6] bfq: fix potential kernel crash when print error info Yufen Yu
2020-03-25 12:38 ` [PATCH v4 4/6] memcg: fix crash in wb_workfn when bdi unregister Yufen Yu
2020-03-25 12:38 ` [PATCH v4 5/6] blk-wbt: replace bdi_dev_name() with bdi_get_dev_name() Yufen Yu
2020-03-25 12:38 ` [PATCH v4 6/6] blkcg: fix use-after-free for bdi->dev Yufen Yu
2020-04-09 13:28 ` [PATCH v4 0/6] bdi: fix use-after-free for bdi device Yufen Yu
2020-04-14 14:44 ` Theodore Y. Ts'o
2020-04-14 15:52 ` Christoph Hellwig
2020-04-15 9:34 ` Jan Kara
2020-04-16 5:36 ` Christoph Hellwig [this message]
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