diff options
| author | David Howells <dhowells@redhat.com> | 2008-11-14 10:39:26 +1100 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2008-11-14 10:39:26 +1100 |
| commit | 3b11a1decef07c19443d24ae926982bc8ec9f4c0 (patch) | |
| tree | b6555f0e5b07f4b2badd332a0a900b974920c49d /include/linux/init_task.h | |
| parent | 98870ab0a5a3f1822aee681d2997017e1c87d026 (diff) | |
CRED: Differentiate objective and effective subjective credentials on a task
Differentiate the objective and real subjective credentials from the effective
subjective credentials on a task by introducing a second credentials pointer
into the task_struct.
task_struct::real_cred then refers to the objective and apparent real
subjective credentials of a task, as perceived by the other tasks in the
system.
task_struct::cred then refers to the effective subjective credentials of a
task, as used by that task when it's actually running. These are not visible
to the other tasks in the system.
__task_cred(task) then refers to the objective/real credentials of the task in
question.
current_cred() refers to the effective subjective credentials of the current
task.
prepare_creds() uses the objective creds as a base and commit_creds() changes
both pointers in the task_struct (indeed commit_creds() requires them to be the
same).
override_creds() and revert_creds() change the subjective creds pointer only,
and the former returns the old subjective creds. These are used by NFSD,
faccessat() and do_coredump(), and will by used by CacheFiles.
In SELinux, current_has_perm() is provided as an alternative to
task_has_perm(). This uses the effective subjective context of current,
whereas task_has_perm() uses the objective/real context of the subject.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'include/linux/init_task.h')
| -rw-r--r-- | include/linux/init_task.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 08c3b24ad9a8..2597858035cd 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -149,6 +149,7 @@ extern struct cred init_cred; .children = LIST_HEAD_INIT(tsk.children), \ .sibling = LIST_HEAD_INIT(tsk.sibling), \ .group_leader = &tsk, \ + .real_cred = &init_cred, \ .cred = &init_cred, \ .cred_exec_mutex = \ __MUTEX_INITIALIZER(tsk.cred_exec_mutex), \ |