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From: Dan Carpenter <error27@gmail.com>
To: Sajal Gupta <sajal2005gupta@gmail.com>
Cc: linux-raid@vger.kernel.org, song@kernel.org, yukuai3@huawei.com,
	tomasz.majchrzak@intel.com, linux-kernel@vger.kernel.org,
	skhan@linuxfoundation.org, me@brighamcampbell.com,
	linux-kernel-mentees@lists.linux.dev
Subject: Re: [PATCH] md/raid5-ppl: convert pending_flushes from atomic_t to refcount_t
Date: Mon, 22 Jun 2026 11:42:01 +0300	[thread overview]
Message-ID: <ajj1WdhoW-Y3GE4Q@stanley.mountain> (raw)
In-Reply-To: <20260622080656.22786-1-sajal2005gupta@gmail.com>

On Mon, Jun 22, 2026 at 01:34:32PM +0530, Sajal Gupta wrote:
> The old atomic_t based counter allowed ppl_do_flush() to continue using io
> after it could already have been freed by ppl_io_unit_finished(), leading
> to a use-after-free.
> 
> Convert pending_flushes from atomic_t to refcount_t with a proper ownership
> model. The creator holds a reference for the duration of ppl_do_flush(),
> and each submitted flush bio holds a reference until its endio callback
> runs. This makes the io lifetime explicit and removes the need for the
> second loop in ppl_do_flush().
> 
> Fixes: 1532d9e87e8b ("raid5-ppl: PPL support for disks with write-back cache enabled")
> Reported-by: Dan Carpenter <error27@gmail.com>
> Closes: https://lore.kernel.org/all/ajJF2wKYWRk4GGCK@stanley.mountain/
> Signed-off-by: Sajal Gupta <sajal2005gupta@gmail.com>
> ---

Have you tested this at all because it doesn't seem at all correct to
me...

regards,
dan carpenter


  reply	other threads:[~2026-06-22  8:42 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-22  8:04 [PATCH] md/raid5-ppl: convert pending_flushes from atomic_t to refcount_t Sajal Gupta
2026-06-22  8:42 ` Dan Carpenter [this message]
2026-06-22  8:43   ` Dan Carpenter
2026-06-22 10:28     ` Sajal Gupta
2026-06-22 10:57       ` Dan Carpenter
2026-06-22 11:28         ` Sajal Gupta
2026-06-22 11:38           ` Dan Carpenter

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