CRED: Wrap task credential accesses in the core kernel
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.
Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-audit@redhat.com
Cc: containers@lists.linux-foundation.org
Cc: linux-mm@kvack.org
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/kernel/sched.c b/kernel/sched.c
index e8819bc..c3b8b1f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5128,6 +5128,7 @@
unsigned long flags;
const struct sched_class *prev_class = p->sched_class;
struct rq *rq;
+ uid_t euid;
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
@@ -5180,8 +5181,9 @@
return -EPERM;
/* can't change other user's priorities */
- if ((current->euid != p->euid) &&
- (current->euid != p->uid))
+ euid = current_euid();
+ if (euid != p->euid &&
+ euid != p->uid)
return -EPERM;
}
@@ -5392,6 +5394,7 @@
cpumask_t cpus_allowed;
cpumask_t new_mask = *in_mask;
struct task_struct *p;
+ uid_t euid;
int retval;
get_online_cpus();
@@ -5412,9 +5415,9 @@
get_task_struct(p);
read_unlock(&tasklist_lock);
+ euid = current_euid();
retval = -EPERM;
- if ((current->euid != p->euid) && (current->euid != p->uid) &&
- !capable(CAP_SYS_NICE))
+ if (euid != p->euid && euid != p->uid && !capable(CAP_SYS_NICE))
goto out_unlock;
retval = security_task_setscheduler(p, 0, NULL);