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From: Ming Lei <ming.lei@redhat.com>
To: Justin Tee <justin.tee@broadcom.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH] block: fix memleak of bio integrity data
Date: Thu, 5 Dec 2019 15:49:32 +0800	[thread overview]
Message-ID: <20191205074932.GA21955@ming.t460p> (raw)
In-Reply-To: <CAAmqgVN6huL60c9aw41yC6wz6fG0w-T4xR0Tuoz0PqX2BqwKDA@mail.gmail.com>

On Wed, Dec 04, 2019 at 09:41:24PM -0800, Justin Tee wrote:
> Hi Ming,
> 
> I understand the patch, but I have a concern.
> 
> Is it possible to come across a double-free?  from bio_endio ->
> bio_integrity_endio -> __bio_integrity_endio -> bio_integrity_free;  And
> then, resuming in bio_endio -> bio_uninit -> bio_integrity_free;.  Maybe
> it's even possible queue_work  bio_integrity_verify_fn was scheduled and
> called bio_integrity_free from there as well.  So, should also remove
> bio_integrity_free from bio_integrity_verify_fn and __bio_integrity_endio
> routines?

Yeah, double-free could be caused for READ between bio_integrity_verify_fn()
and bio_uninit().

I think it is enough to remove bio_integrity_free() from both
bio_integrity_verify_fn() and __bio_integrity_endio().

Will do it in V2.


Thanks, 
Ming


  parent reply	other threads:[~2019-12-05  7:49 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-05  2:09 [PATCH] block: fix memleak of bio integrity data Ming Lei
     [not found] ` <CAAmqgVN6huL60c9aw41yC6wz6fG0w-T4xR0Tuoz0PqX2BqwKDA@mail.gmail.com>
2019-12-05  7:49   ` Ming Lei [this message]
2019-12-05  8:09     ` Ming Lei
2019-12-05 18:30       ` Justin Tee
2019-12-05 18:38         ` Jens Axboe
2019-12-05  9:52 ` Christoph Hellwig
2019-12-05 10:08 ` John Garry

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