WSL2-Linux-Kernel/security
Aristeu Rozanski bd2953ebbb devcg: propagate local changes down the hierarchy
This patch makes exception changes to propagate down in hierarchy respecting
when possible local exceptions.

New exceptions allowing additional access to devices won't be propagated, but
it'll be possible to add an exception to access all of part of the newly
allowed device(s).

New exceptions disallowing access to devices will be propagated down and the
local group's exceptions will be revalidated for the new situation.
Example:
      A
     / \
        B

    group        behavior          exceptions
    A            allow             "b 8:* rwm", "c 116:1 rw"
    B            deny              "c 1:3 rwm", "c 116:2 rwm", "b 3:* rwm"

If a new exception is added to group A:
	# echo "c 116:* r" > A/devices.deny
it'll propagate down and after revalidating B's local exceptions, the exception
"c 116:2 rwm" will be removed.

In case parent's exceptions change and local exceptions are not allowed anymore,
they'll be deleted.

v7:
- do not allow behavior change when the cgroup has children
- update documentation

v6: fixed issues pointed by Serge Hallyn
- only copy parent's exceptions while propagating behavior if the local
  behavior is different
- while propagating exceptions, do not clear and copy parent's: it'd be against
  the premise we don't propagate access to more devices

v5: fixed issues pointed by Serge Hallyn
- updated documentation
- not propagating when an exception is written to devices.allow
- when propagating a new behavior, clean the local exceptions list if they're
  for a different behavior

v4: fixed issues pointed by Tejun Heo
- separated function to walk the tree and collect valid propagation targets

v3: fixed issues pointed by Tejun Heo
- update documentation
- move css_online/css_offline changes to a new patch
- use cgroup_for_each_descendant_pre() instead of own descendant walk
- move exception_copy rework to a separared patch
- move exception_clean rework to a separated patch

v2: fixed issues pointed by Tejun Heo
- instead of keeping the local settings that won't apply anymore, remove them

Cc: Tejun Heo <tj@kernel.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-03-20 07:50:21 -07:00
..
apparmor new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
integrity hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
keys KEYS: Revert one application of "Fix unreachable code" patch 2013-02-21 07:56:25 -08:00
selinux Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
smack new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
tomoyo new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
yama Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-17 15:44:47 -08:00
Kconfig KEYS: Move the key config into security/keys/Kconfig 2012-05-11 10:56:56 +01:00
Makefile security: Yama LSM 2012-02-10 09:18:52 +11:00
capability.c tun: fix LSM/SELinux labeling of tun/tap devices 2013-01-14 18:16:59 -05:00
commoncap.c kill f_vfsmnt 2013-02-26 02:46:10 -05:00
device_cgroup.c devcg: propagate local changes down the hierarchy 2013-03-20 07:50:21 -07:00
inode.c securityfs: fix object creation races 2012-01-10 10:20:35 -05:00
lsm_audit.c LSM: BUILD_BUG_ON if the common_audit_data union ever grows 2012-04-09 12:23:03 -04:00
min_addr.c mmap_min_addr check CAP_SYS_RAWIO only for write 2010-04-23 08:56:31 +10:00
security.c tun: fix LSM/SELinux labeling of tun/tap devices 2013-01-14 18:16:59 -05:00