From: Al Viro <viro@zeniv.linux.org.uk>
To: Denis Arefev <arefev@swemel.ru>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
lvc-project@linuxtesting.org, stable@vger.kernel.org
Subject: Re: [PATCH] block: Avoid mounting the bdev pseudo-filesystem in userspace
Date: Tue, 2 Jun 2026 02:19:07 +0100 [thread overview]
Message-ID: <20260602011907.GM2636677@ZenIV> (raw)
In-Reply-To: <20260521072857.5078-1-arefev@swemel.ru>
On Thu, May 21, 2026 at 10:28:56AM +0300, Denis Arefev wrote:
> The bdev pseudo-filesystem is an internal kernel filesystem with which
> userspace should not interfere. Unregister it so that userspace cannot
> even attempt to mount it.
>
> This fixes a bug [1] that occurs when attempting to access files,
> because the system call move_mount() uses pointers declared in the
> inode_operations structure, which for the bdev pseudo-filesystem
> are always equal to 0. `inode->i_op = &empty_iops;`
What? init_pseudo() sets SB_NOUSER; what are you talking about?
And assuming you've somehow managed to mount the sucker, which
->i_op method had been accessed?
next prev parent reply other threads:[~2026-06-02 1:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-21 7:28 [PATCH] block: Avoid mounting the bdev pseudo-filesystem in userspace Denis Arefev
2026-05-25 6:07 ` Christoph Hellwig
2026-06-02 1:21 ` Al Viro
2026-05-26 16:37 ` Jens Axboe
2026-06-02 1:19 ` Al Viro [this message]
2026-06-02 1:35 ` Al Viro
2026-06-02 2:04 ` [PATCH] make new mount API honour SB_NOUSER (was Re: [PATCH] block: Avoid mounting the bdev pseudo-filesystem in userspace) Al Viro
2026-06-02 9:11 ` Jan Kara
2026-06-02 13:23 ` Arefev
2026-06-02 14:54 ` Al Viro
2026-06-02 14:07 ` Al Viro
2026-06-02 14:55 ` Christian Brauner
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