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From: Christoph Hellwig <hch@lst.de>
To: Jingbo Xu <jefflexu@linux.alibaba.com>
Cc: axboe@kernel.dk, hch@lst.de, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, tianjia.zhang@linux.alibaba.com,
	xiang@kernel.org, casey@schaufler-ca.com
Subject: Re: [RFC] block: relax permission for Persistent Reservations ioctl
Date: Sat, 10 Jun 2023 08:06:26 +0200	[thread overview]
Message-ID: <20230610060626.GA1595@lst.de> (raw)
In-Reply-To: <20230609102122.118800-1-jefflexu@linux.alibaba.com>

On Fri, Jun 09, 2023 at 06:21:22PM +0800, Jingbo Xu wrote:
> When the shared storage is accessed from containers [1], it's not
> recommended to grant CAP_SYS_ADMIN to containers for access to
> Persistent Reservations in risk of container escape.
> 
> Remove the extra CAP_SYS_ADMIN permission constraint for Persistent
> Reservations ioctl which shall do no harm [2].

I think we still to check that if CAP_SYS_ADMIN is not present,
the file descriptors needs to be open for write, and we're not called
on a partition (the latter should probbaly be always checked,
as a reservation for a partitions doesn't make sense).

But in general I think relaxing this is a good idea, we just need to
be very careful.  Looking at the discussion of unprivileged nvme
command passthrough might be a good start.

  reply	other threads:[~2023-06-10  6:06 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-09 10:21 [RFC] block: relax permission for Persistent Reservations ioctl Jingbo Xu
2023-06-10  6:06 ` Christoph Hellwig [this message]
2023-06-10  8:12   ` Jingbo Xu

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