From: Christoph Hellwig <hch@infradead.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Hellwig <hch@infradead.org>, Jan Kara <jack@suse.cz>,
Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, Ted Tso <tytso@mit.edu>,
yebin <yebin@huaweicloud.com>,
linux-fsdevel@vger.kernel.org,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: [PATCH] block: Add config option to not allow writing to mounted devices
Date: Wed, 14 Jun 2023 00:17:26 -0700 [thread overview]
Message-ID: <ZIlphqM9cpruwU6m@infradead.org> (raw)
In-Reply-To: <CACT4Y+ZsN3wemvGLVyNWj9zjykGwcHoy581w7GuAHGpAj1YLxg@mail.gmail.com>
On Tue, Jun 13, 2023 at 08:09:14AM +0200, Dmitry Vyukov wrote:
> I don't question there are use cases for the flag, but there are use
> cases for the config as well.
>
> Some distros may want a guarantee that this does not happen as it
> compromises lockdown and kernel integrity (on par with unsigned module
> loading).
> For fuzzing systems it also may be hard to ensure fine-grained
> argument constraints, it's much easier and more reliable to prohibit
> it on config level.
I'm fine with a config option enforcing write blocking for any
BLK_OPEN_EXCL open. Maybe the way to it is to:
a) have an option to prevent any writes to exclusive openers, including
a run-time version to enable it
b) allow to also block writes without that option. And maybe an
opt-in to allow writes might be the better way than doing it
the other way around.
next prev parent reply other threads:[~2023-06-14 7:18 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-12 16:16 [PATCH] block: Add config option to not allow writing to mounted devices Jan Kara
2023-06-12 16:25 ` Jan Kara
2023-06-12 17:39 ` Bart Van Assche
2023-06-12 17:47 ` Theodore Ts'o
2023-06-12 18:52 ` Colin Walters
2023-06-13 11:34 ` Jan Kara
2023-06-14 1:55 ` Darrick J. Wong
2023-06-14 7:14 ` Christoph Hellwig
2023-06-14 7:05 ` Christian Brauner
2023-06-14 7:07 ` Christoph Hellwig
2023-06-14 7:10 ` Christoph Hellwig
2023-06-14 10:12 ` Jan Kara
2023-06-14 14:30 ` Christoph Hellwig
2023-06-14 14:46 ` Matthew Wilcox
2023-06-13 4:56 ` kernel test robot
2023-06-13 5:10 ` Christoph Hellwig
2023-06-13 6:09 ` Dmitry Vyukov
2023-06-14 7:17 ` Christoph Hellwig [this message]
2023-06-14 8:18 ` Christian Brauner
2023-06-14 10:36 ` Jan Kara
2023-06-14 12:48 ` Christian Brauner
2023-06-15 14:39 ` Jan Kara
2023-06-14 14:31 ` Christoph Hellwig
2023-06-13 20:56 ` Jan Kara
2023-06-14 7:20 ` Christoph Hellwig
2023-06-20 10:41 ` Jan Kara
2023-06-20 11:29 ` Christoph Hellwig
2023-06-14 7:35 ` Christian Brauner
2023-06-13 6:49 ` Dmitry Vyukov
2023-06-13 19:22 ` Theodore Ts'o
2023-06-14 0:26 ` Dave Chinner
2023-06-14 2:04 ` Darrick J. Wong
2023-06-14 2:57 ` Theodore Ts'o
2023-06-14 12:27 ` Dmitry Vyukov
2023-06-14 23:38 ` Dave Chinner
2023-06-15 9:14 ` Dmitry Vyukov
2023-06-18 23:35 ` Dave Chinner
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