From: Tejun Heo <tj@kernel.org>
To: Jan Kara <jack@suse.cz>
Cc: Yufen Yu <yuyufen@huawei.com>,
axboe@kernel.dk, linux-block@vger.kernel.org, bvanassche@acm.org
Subject: Re: [PATCH] bdi: fix use-after-free for bdi device
Date: Wed, 19 Feb 2020 10:12:00 -0500 [thread overview]
Message-ID: <20200219151200.GA698990@mtj.thefacebook.com> (raw)
In-Reply-To: <20200219125505.GP16121@quack2.suse.cz>
Hello, Jan.
On Wed, Feb 19, 2020 at 01:55:05PM +0100, Jan Kara wrote:
> Also I was wondering about one thing: If we really care about bdi->dev only
> for the name, won't we be much better off with just copying the name to
> bdi->name on registration? Sure it would consume a bit of memory for the
> name copy but I don't think we really care and things would be IMO *much*
> simpler that way... Yufen, Tejun, what do you think?
Yeah, could be. So, object lifetimes in block layer have been kinda
janky mostly for historical reasons and in a lot of cases ppl apply
bandaids to work around immediate problems and at other times things
get restructured and properly fixed. Given how the objects are used
here, it'd be a typical case for RCU protecting bdi->dev and I wonder,
in the longer term, that'd be a better way to go than special-casing
name. That said, it's not a strong opinion.
Thanks.
--
tejun
next prev parent reply other threads:[~2020-02-19 15:12 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-11 14:00 [PATCH] bdi: fix use-after-free for bdi device Yufen Yu
2020-02-11 13:57 ` Yufen Yu
2020-02-12 21:33 ` Tejun Heo
2020-02-13 2:46 ` Yufen Yu
2020-02-13 3:48 ` Tejun Heo
2020-02-13 7:51 ` Yufen Yu
2020-02-13 13:58 ` Tejun Heo
2020-02-14 2:50 ` Yufen Yu
2020-02-14 14:05 ` Tejun Heo
2020-02-15 13:54 ` Yufen Yu
2020-02-19 12:55 ` Jan Kara
2020-02-19 15:12 ` Tejun Heo [this message]
2020-02-20 11:07 ` Yufen Yu
2020-02-20 12:07 ` Jan Kara
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