diff options
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a48de6ab066..e1d826a2cd8 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2184,6 +2184,24 @@ out_free_group_list: return retval; } +static int cgroup_allow_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) +{ + struct cgroup_subsys *ss; + int ret; + + for_each_subsys(cgrp->root, ss) { + if (ss->allow_attach) { + ret = ss->allow_attach(cgrp, tset); + 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 lock @@ -2215,9 +2233,18 @@ retry_find_task: if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) && !uid_eq(cred->euid, tcred->uid) && !uid_eq(cred->euid, tcred->suid)) { - rcu_read_unlock(); - ret = -EACCES; - goto out_unlock_cgroup; + /* + * if the default permission check fails, give each + * cgroup a chance to extend the permission check + */ + struct cgroup_taskset tset = { }; + tset.single.task = tsk; + tset.single.cgrp = cgrp; + ret = cgroup_allow_attach(cgrp, &tset); + if (ret) { + rcu_read_unlock(); + goto out_unlock_cgroup; + } } } else tsk = current; |