setns on a cgroup namespace is allowed only if task has CAP_SYS_ADMIN in its current user-namespace and over the user-namespace associated with target cgroupns. No implicit cgroup changes happen with attaching to another cgroupns. It is expected that the somone moves the attaching process under the target cgroupns-root.
Signed-off-by: Aditya Kali <[email protected]> --- kernel/cgroup_namespace.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup_namespace.c b/kernel/cgroup_namespace.c index 7e9bda0..0803575 100644 --- a/kernel/cgroup_namespace.c +++ b/kernel/cgroup_namespace.c @@ -86,8 +86,22 @@ err_out: static int cgroupns_install(struct nsproxy *nsproxy, void *ns) { - pr_info("setns not supported for cgroup namespace"); - return -EINVAL; + struct cgroup_namespace *cgroup_ns = ns; + + if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) || + !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN)) + return -EPERM; + + /* Prevent cgroup changes for this task. */ + threadgroup_lock(current); + + get_cgroup_ns(cgroup_ns); + put_cgroup_ns(nsproxy->cgroup_ns); + nsproxy->cgroup_ns = cgroup_ns; + + threadgroup_unlock(current); + + return 0; } static void *cgroupns_get(struct task_struct *task) -- 2.1.0.rc2.206.gedb03e5 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
