diff options
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 84dd3818633f..bab5a7911b84 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2202,6 +2202,24 @@ out_free_group_list: return retval; } +static int cgroup_allow_attach(struct cgroup *cgrp, struct task_struct *tsk) +{ + struct cgroup_subsys *ss; + int ret; + + for_each_subsys(cgrp->root, ss) { + if (ss->allow_attach) { + ret = ss->allow_attach(cgrp, tsk); + if (ret) + return ret; + } else { + return -EACCES; + } + } + + return 0; +} + /* * Find the task_struct of the task to attach by vpid and pass it along to the * function to attach either it or all tasks in its threadgroup. Will take @@ -2247,9 +2265,16 @@ static int attach_task_by_pid(struct cgroup *cgrp, u64 pid, bool threadgroup) if (cred->euid && cred->euid != tcred->uid && cred->euid != tcred->suid) { - rcu_read_unlock(); - cgroup_unlock(); - return -EACCES; + /* + * if the default permission check fails, give each + * cgroup a chance to extend the permission check + */ + ret = cgroup_allow_attach(cgrp, tsk); + if (ret) { + rcu_read_unlock(); + cgroup_unlock(); + return ret; + } } get_task_struct(tsk); rcu_read_unlock(); |