From: Eric Biggers <ebiggers@kernel.org>
To: Al Viro <viro@zeniv.linux.org.uk>, David Howells <dhowells@redhat.com>
Cc: 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: Tue, 2 Jul 2019 11:22:59 -0700 [thread overview]
Message-ID: <20190702182258.GB110306@gmail.com> (raw)
In-Reply-To: <20190701182239.GA17978@ZenIV.linux.org.uk>
On Mon, Jul 01, 2019 at 07:22:39PM +0100, Al Viro wrote:
> On Mon, Jul 01, 2019 at 09:45:37AM -0700, Eric Biggers wrote:
> > On Sat, Jun 29, 2019 at 01:27:44PM -0700, Eric Biggers wrote:
> > >
> > > Reproducer:
> > >
> > > #include <unistd.h>
> > >
> > > #define __NR_move_mount 429
> > > #define MOVE_MOUNT_F_EMPTY_PATH 0x00000004
> > >
> > > int main()
> > > {
> > > int fds[2];
> > >
> > > pipe(fds);
> > > syscall(__NR_move_mount, fds[0], "", -1, "/", MOVE_MOUNT_F_EMPTY_PATH);
> > > }
> >
> > David, I'd like to add this as a regression test somewhere.
> >
> > Can you point me to the tests for the new mount syscalls?
> >
> > I checked LTP, kselftests, and xfstests, but nothing to be found.
>
> 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...
Sure, but the new mount syscalls still need tests. Where are the tests?
Also, since the case of a fd with an internal mount was overlooked, probably the
man page needs to be updated clarify that move_mount(2) fails with EINVAL in
this case. Where is the man page?
- Eric
next prev parent reply other threads:[~2019-07-02 18:23 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
2019-07-02 18:22 ` Eric Biggers [this message]
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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