[PATCH v2 0/2] implement OA2_INHERIT_CRED flag for openat2()

[Stas Sergeev <stsp2@yandex.ru>]

This patch-set implements the OA2_INHERIT_CRED flag for openat2() syscall.
It is needed to perform an open operation with the creds that were in
effect when the dir_fd was opened. This allows the process to pre-open
some dirs and switch eUID (and other UIDs/GIDs) to the less-privileged
user, while still retaining the possibility to open/create files within
the pre-opened directory set.

Changes in v2:
- capture full struct cred instead of just fsuid/fsgid.
  Suggested by Stefan Metzmacher <metze@samba.org>


Stas Sergeev (2):
  fs: reorganize path_openat()
  openat2: add OA2_INHERIT_CRED flag

 fs/internal.h                |  2 +-
 fs/namei.c                   | 52 +++++++++++++++++++++++++++++-------
 fs/open.c                    |  2 +-
 include/linux/fcntl.h        |  2 ++
 include/uapi/linux/openat2.h |  3 +++
 5 files changed, 50 insertions(+), 11 deletions(-)

-- 
2.44.0