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From: Al Viro <viro@zeniv.linux.org.uk>
To: David Howells <dhowells@redhat.com>
Cc: Eric Biggers <ebiggers@kernel.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH] vfs: move_mount: reject moving kernel internal mounts
Date: Mon, 1 Jul 2019 12:19:51 +0100	[thread overview]
Message-ID: <20190701111950.GY17978@ZenIV.linux.org.uk> (raw)
In-Reply-To: <2578.1561966690@warthog.procyon.org.uk>

On Mon, Jul 01, 2019 at 08:38:10AM +0100, David Howells wrote:
> Al Viro <viro@zeniv.linux.org.uk> wrote:
> 
> > 	/* The thing moved must be mounted... */
> > 	if (!is_mounted(old_path->mnt))
> > 		goto out;
> 
> Um...  Doesn't that stuff up fsmount()?

Nope - check is_mounted() definition.  Stuff in anon namespace
*is* mounted there, so that's not a problem.

FWIW, is_mounted() would've been better off spelled as
ns != NULL && ns != MNT_NS_INTERNAL; the use of IS_ERR_OR_NULL
in there works, but is unidiomatic and I don't think it yields
better code...

  reply	other threads:[~2019-07-01 11:19 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-18 10:47 general protection fault in do_move_mount (2) syzbot
2019-06-18 14:02 ` Al Viro
2019-06-24  9:28   ` Dmitry Vyukov
2019-06-29 20:27     ` [PATCH] vfs: move_mount: reject moving kernel internal mounts Eric Biggers
2019-06-29 20:39       ` Al Viro
2019-07-01  1:08         ` Al Viro
2019-07-01 15:43           ` Eric Biggers
2019-07-01  7:38         ` David Howells
2019-07-01 11:19           ` Al Viro [this message]
2019-07-01 16:45       ` Eric Biggers
2019-07-01 18:22         ` Al Viro
2019-07-01 19:20           ` Al Viro
2019-07-02 18:22           ` Eric Biggers
2019-07-09 19:40             ` Eric Biggers
2019-07-09 20:54               ` Al Viro
2019-07-10  3:23                 ` 6 new syscalls without tests (was: [PATCH] vfs: move_mount: reject moving kernel internal mounts) Eric Biggers
2019-07-05  9:01           ` move_mount.2 David Howells
2019-06-29 20:39     ` general protection fault in do_move_mount (2) Eric Biggers
2019-07-01 14:59       ` Dmitry Vyukov
2019-07-01 15:18         ` Eric Biggers
2019-07-05 12:17           ` Dmitry Vyukov
2019-07-05 13:02           ` Dmitry Vyukov

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