[PATCH v4 0/3] proc: Relax check of mount visibility

From: Alexey Gladkov <gladkov.alexey@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>,
	Linux FS Devel <linux-fsdevel@vger.kernel.org>,
	"Eric W . Biederman" <ebiederm@xmission.com>
Cc: Alexey Gladkov <legion@kernel.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Kees Cook <keescook@chromium.org>
Subject: [PATCH v4 0/3] proc: Relax check of mount visibility
Date: Fri,  6 Nov 2020 16:15:09 +0100	[thread overview]
Message-ID: <cover.1604675649.git.gladkov.alexey@gmail.com> (raw)

If only the dynamic part of procfs is mounted (subset=pid), then there is no
need to check if procfs is fully visible to the user in the new user namespace.

Changelog
---------
v4:
* Set SB_I_DYNAMIC only if pidonly is set.
* Add an error message if subset=pid is canceled during remount.

v3:
* Add 'const' to struct cred *mounter_cred (fix kernel test robot warning).

v2:
* cache the mounters credentials and make access to the net directories
  contingent of the permissions of the mounter of procfs.

--

Alexey Gladkov (3):
  proc: Relax check of mount visibility
  proc: Show /proc/self/net only for CAP_NET_ADMIN
  proc: Disable cancellation of subset=pid option

 fs/namespace.c          | 27 ++++++++++++++++-----------
 fs/proc/proc_net.c      |  8 ++++++++
 fs/proc/root.c          | 29 ++++++++++++++++++++++-------
 include/linux/fs.h      |  1 +
 include/linux/proc_fs.h |  1 +
 5 files changed, 48 insertions(+), 18 deletions(-)

-- 
2.25.4