From: Sagi Grimberg <sagi@grimberg.me>
To: "Ewan D. Milne" <emilne@redhat.com>, Daniel Wagner <dwagner@suse.de>
Cc: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
Jens Axboe <axboe@fb.com>, Hannes Reinecke <hare@suse.de>,
Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v2] nvme-tcp: Check if request has started before processing it
Date: Tue, 30 Mar 2021 10:34:25 -0700 [thread overview]
Message-ID: <ed3ccac0-79ed-fe10-89eb-d403820b4c6a@grimberg.me> (raw)
In-Reply-To: <2fc7a320c86f75507584453dd2fbd744de5c170d.camel@redhat.com>
>> It is, but in this situation, the controller is sending a second
>> completion that results in a use-after-free, which makes the
>> transport irrelevant. Unless there is some other flow (which is
>> unclear
>> to me) that causes this which is a bug that needs to be fixed rather
>> than hidden with a safeguard.
>>
>
> The kernel should not crash regardless of any network traffic that is
> sent to the system. It should not be possible to either intentionally
> of mistakenly contruct packets that will deny service in this way.
This is not specific to nvme-tcp. I can build an rdma or pci controller
that can trigger the same crash... I saw a similar patch from Hannes
implemented in the scsi level, and not the individual scsi transports..
I would also mention, that a crash is not even the scariest issue that
we can see here, because if the request happened to be reused we are
in the silent data corruption realm...
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next prev parent reply other threads:[~2021-03-30 17:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-01 17:56 [PATCH v2] nvme-tcp: Check if request has started before processing it Daniel Wagner
2021-03-05 19:57 ` Sagi Grimberg
2021-03-11 9:43 ` Daniel Wagner
2021-03-15 17:16 ` Sagi Grimberg
2021-03-30 16:19 ` Ewan D. Milne
2021-03-30 17:34 ` Sagi Grimberg [this message]
2021-03-30 23:28 ` Keith Busch
2021-03-31 7:11 ` Hannes Reinecke
2021-03-31 21:01 ` Ewan D. Milne
2021-03-31 22:24 ` Sagi Grimberg
2021-04-01 6:20 ` Christoph Hellwig
2021-04-01 8:25 ` Sagi Grimberg
2021-03-31 22:37 ` Sagi Grimberg
2021-05-06 15:36 ` Hannes Reinecke
2021-05-07 20:26 ` Sagi Grimberg
2021-05-07 20:40 ` Keith Busch
2021-05-07 23:22 ` Sagi Grimberg
2021-05-08 0:03 ` Keith Busch
2021-05-09 11:30 ` Hannes Reinecke
2021-05-11 18:16 ` Sagi Grimberg
2021-05-17 14:58 ` Daniel Wagner
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