linux/include
David Howells b206f281d0 keys: Namespace keyring names
Keyring names are held in a single global list that any process can pick
from by means of keyctl_join_session_keyring (provided the keyring grants
Search permission).  This isn't very container friendly, however.

Make the following changes:

 (1) Make default session, process and thread keyring names begin with a
     '.' instead of '_'.

 (2) Keyrings whose names begin with a '.' aren't added to the list.  Such
     keyrings are system specials.

 (3) Replace the global list with per-user_namespace lists.  A keyring adds
     its name to the list for the user_namespace that it is currently in.

 (4) When a user_namespace is deleted, it just removes itself from the
     keyring name list.

The global keyring_name_lock is retained for accessing the name lists.
This allows (4) to work.

This can be tested by:

	# keyctl newring foo @s
	995906392
	# unshare -U
	$ keyctl show
	...
	 995906392 --alswrv  65534 65534   \_ keyring: foo
	...
	$ keyctl session foo
	Joined session keyring: 935622349

As can be seen, a new session keyring was created.

The capability bit KEYCTL_CAPS1_NS_KEYRING_NAME is set if the kernel is
employing this feature.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric W. Biederman <ebiederm@xmission.com>
2019-06-26 21:02:32 +01:00
..
acpi More ACPI updates for 5.2-rc1 2019-05-15 08:58:49 -07:00
asm-generic Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-19 10:23:24 -07:00
clocksource
crypto
drm drm pull request for 5.2 2019-05-08 21:35:19 -07:00
dt-bindings ARM: Device-tree updates 2019-05-16 08:38:17 -07:00
keys keys: Move the RCU locks outwards from the keyring search functions 2019-06-19 16:10:15 +01:00
kvm
linux keys: Namespace keyring names 2019-06-26 21:02:32 +01:00
math-emu
media media updates for v5.2-rc1 2019-05-16 11:57:16 -07:00
memory
misc ocxl: Provide global MMIO accessors for external drivers 2019-05-03 02:55:02 +10:00
net AFS fixes 2019-05-16 17:00:13 -07:00
pcmcia
ras
rdma RDMA: Add EFA related definitions 2019-05-06 13:47:50 -03:00
scsi
soc Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-19 11:11:20 -07:00
sound sound fixes for 5.2-rc1 2019-05-17 13:57:54 -07:00
target
trace The major changes in this tracing update includes: 2019-05-15 16:05:47 -07:00
uapi keys: Namespace keyring names 2019-06-26 21:02:32 +01:00
video
xen