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From: Keith Busch <kbusch@kernel.org>
To: Weiping Zhang <zhangweiping@didiglobal.com>
Cc: hch@infradead.org, axboe@kernel.dk, sagi@grimberg.me,
	linux-nvme@lists.infradead.org
Subject: Re: [PATCH 1/2] nvme: make sure write/poll_queues less or equal then cpu count
Date: Thu, 9 Apr 2020 10:22:50 -0700	[thread overview]
Message-ID: <20200409172250.GA1889561@dhcp-10-100-145-180.wdl.wdc.com> (raw)
In-Reply-To: <134d9a5fbcf54c1efb8ffa33a5439cd48094925c.1586447291.git.zhangweiping@didiglobal.com>

On Thu, Apr 09, 2020 at 11:57:35PM +0800, Weiping Zhang wrote:
> Check module parameter write/poll_queues before use, if user
> change them to larger than system cpu count, it will trigger a
> warning.
> 
> Reproduce:
> 
> echo $((`nproc`+1)) > /sys/module/nvme/parameters/write_queues
> echo 1 > /sys/block/nvme0n1/device/reset_controller

I don't think it is safe to allow these parameters to be runtime writeable
with the current code: the driver allocates space for queues during probe,
so you may end up with out of bounds access if you increase the number
of queues the driver creates after that.

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  reply	other threads:[~2020-04-09 17:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-09 15:57 [PATCH 0/2] verify module parameter write_queues and poll_queues Weiping Zhang
2020-04-09 15:57 ` [PATCH 1/2] nvme: make sure write/poll_queues less or equal then cpu count Weiping Zhang
2020-04-09 17:22   ` Keith Busch [this message]
2020-04-10  9:56     ` weiping zhang
2020-04-09 15:57 ` [PATCH 2/2] nvme: no need check write/poll_queues in nvme_init Weiping Zhang

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