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From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>, qemu-devel@nongnu.org
Cc: Fam Zheng <fam@euphon.net>, Markus Armbruster <armbru@redhat.com>,
	qemu-block@nongnu.org, Kevin Wolf <kwolf@redhat.com>,
	Max Reitz <mreitz@redhat.com>,
	Prasad J Pandit <ppandit@redhat.com>, Bandan Das <bsd@redhat.com>
Subject: Re: [PATCH 3/3] docs/secure-coding-practices: Describe null-co/zeroes-co block drivers
Date: Wed, 10 Mar 2021 15:40:59 +0300	[thread overview]
Message-ID: <42d495fc-c16c-3a8b-40e5-efd24a0f8251@virtuozzo.com> (raw)
In-Reply-To: <20210310114314.1068957-4-philmd@redhat.com>

10.03.2021 14:43, Philippe Mathieu-Daudé wrote:
> Document that security reports must not use the 'null-co' block
> driver, as it leaves memory uninitialized on purposed (this is
> a performance feature).
> Reports must be send using the 'zeroes-co' driver.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>   docs/devel/secure-coding-practices.rst | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/docs/devel/secure-coding-practices.rst b/docs/devel/secure-coding-practices.rst
> index cbfc8af67e6..64d61085804 100644
> --- a/docs/devel/secure-coding-practices.rst
> +++ b/docs/devel/secure-coding-practices.rst
> @@ -104,3 +104,10 @@ structures and only process the local copy.  This prevents
>   time-of-check-to-time-of-use (TOCTOU) race conditions that could cause QEMU to
>   crash when a vCPU thread modifies guest RAM while device emulation is
>   processing it.
> +
> +Use of null-co / zeroes-co block drivers
> +----------------------------------------
> +
> +When reporting security issues, the null-co block driver must not be used,
> +as it is designed for performance and its read accesses are not initialized.
> +The zeroes-co block driver must be used instead.
> 

How much it differs from just document that when reporting security issues the null-co block driver must be used with read-zeroes=true?

-- 
Best regards,
Vladimir


  reply	other threads:[~2021-03-10 12:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-10 11:43 [PATCH 0/3] block: Introduce the 'zeroes-co' driver to help security reports Philippe Mathieu-Daudé
2021-03-10 11:43 ` [PATCH 1/3] block: Introduce the 'zeroes-co' driver Philippe Mathieu-Daudé
2021-03-10 11:43 ` [RFC PATCH 2/3] tests/test-blockjob: Use zeroes-co instead of null-co, read-zeroes=on Philippe Mathieu-Daudé
2021-03-10 11:43 ` [PATCH 3/3] docs/secure-coding-practices: Describe null-co/zeroes-co block drivers Philippe Mathieu-Daudé
2021-03-10 12:40   ` Vladimir Sementsov-Ogievskiy [this message]
2021-03-10 11:55 ` [PATCH 0/3] block: Introduce the 'zeroes-co' driver to help security reports Daniel P. Berrangé
2021-03-10 12:29   ` Philippe Mathieu-Daudé
2021-03-10 12:32 ` Fam Zheng
2021-03-10 12:37   ` Philippe Mathieu-Daudé
2021-03-10 14:24     ` Fam Zheng

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