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

From: Alexey Gladkov
Date: Wed Feb 17 2021 - 03:22:44 EST


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(-)

--
2.29.2