From: Al Viro <viro@zeniv.linux.org.uk>
To: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>,
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 20:20:49 +0100 [thread overview]
Message-ID: <20190701192049.GB17978@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20190701182239.GA17978@ZenIV.linux.org.uk>
On Mon, Jul 01, 2019 at 07:22:39PM +0100, Al Viro wrote:
> FWIW, it's not just move_mount(2) - I'd expect
>
> int fds[2];
> char s[80];
>
> pipe(fds);
> sprintf(s, "/dev/fd/%d", fds[0]);
> mount(s, "/dev/null", NULL, MS_MOVE, 0);
>
> to step into exactly the same thing. mount(2) does follow symlinks -
> always had...
The same goes for e.g.
#define _GNU_SOURCE
#include <sched.h>
#include <sys/mount.h>
#include <stdio.h>
#include <sys/epoll.h>
main()
{
char s[80];
unshare(CLONE_NEWNS); // so nobody else gets confused
sprintf(s, "/dev/fd/%d", epoll_create1(0));
mount(s, "/dev/null", NULL, MS_MOVE, 0); // see if it oopses
}
modulo error-checking, etc.
next prev parent reply other threads:[~2019-07-01 19:20 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
2019-07-01 16:45 ` Eric Biggers
2019-07-01 18:22 ` Al Viro
2019-07-01 19:20 ` Al Viro [this message]
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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