lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Thu,  5 Apr 2018 12:51:00 +0200
From:   Christian Brauner <christian.brauner@...ntu.com>
To:     torvalds@...ux-foundation.org, viro@...iv.linux.org.uk,
        ebiederm@...ssion.com, linux-kernel@...r.kernel.org
Cc:     Christian Brauner <christian.brauner@...ntu.com>
Subject: [PATCH 0/3 RESEND] namei: add follow_up_bind()

Hi everyone,

(Resending since Linus email got mangled on my terminal. Sorry.)

Back when we fixed TIOCGPTPEER again in

commit a319b01d9095 ("devpts: resolve devpts bind-mounts")

we discovered [1] that the code for bind-mount resolution we needed to add
in devpts_mtnget() was already duplicated in nfsd code. So we briefly
discussed [2] adding a helper to namei.{c,h} that would resolve
bind-mounts. The bind-mount resolution code is replicated in at least two
places:
- fs/nfsd/vfs.c:follow_to_parent()
- fs/devpts/inode.c:devpts_mntget()

This series adds:
- follow_up_bind() to namei.{c,h}
- switches fs/nfsd/vfs.c:follow_to_parent() to use follow_up_bind()
- switches fs/devpts/inode.c:devpts_mntget() to use follow_up_bind()

I just wanted to wait until the devpts patches I sent would make it into
mainline. Seems to me that this helper might be worth having around. Not
just because it avoids (granted rather trivial) code duplication but also
because it makes the concept of resolving a bind-mount up to the origin
mountpoint of the vfs's mount obvious (which at least to me wasn't
obivous before).

[1]: https://lkml.org/lkml/2018/3/11/219
[2]: https://lkml.org/lkml/2018/3/12/486

Thanks!
Christian

Christian Brauner (3):
  namei: add follow_up_bind()
  devpts: use follow_up_bind() helper
  nfsd: use follow_up_bind() helper

 fs/devpts/inode.c     |  4 +---
 fs/namei.c            | 10 ++++++++++
 fs/nfsd/vfs.c         |  4 ++--
 include/linux/namei.h |  1 +
 4 files changed, 14 insertions(+), 5 deletions(-)

-- 
2.15.1

Powered by blists - more mailing lists