capabilities: allow nice if we are privileged

We allow task A to change B's nice level if it has a supserset of
B's privileges, or of it has CAP_SYS_NICE.  Also allow it if A has
CAP_SYS_NICE with respect to B - meaning it is root in the same
namespace, or it created B's namespace.

Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Serge Hallyn 2013-07-23 13:18:53 -05:00 committed by Eric W. Biederman
parent 6e556ce209
commit f54fb863c6

View File

@ -768,16 +768,16 @@ int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
*/
static int cap_safe_nice(struct task_struct *p)
{
int is_subset;
int is_subset, ret = 0;
rcu_read_lock();
is_subset = cap_issubset(__task_cred(p)->cap_permitted,
current_cred()->cap_permitted);
if (!is_subset && !ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE))
ret = -EPERM;
rcu_read_unlock();
if (!is_subset && !capable(CAP_SYS_NICE))
return -EPERM;
return 0;
return ret;
}
/**