From mboxrd@z Thu Jan 1 00:00:00 1970 From: serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org Subject: [PATCH 4/8] cgroup: cgroup namespace setns support Date: Tue, 22 Dec 2015 22:23:25 -0600 Message-ID: <1450844609-9194-5-git-send-email-serge.hallyn@ubuntu.com> References: <1450844609-9194-1-git-send-email-serge.hallyn@ubuntu.com> Return-path: In-Reply-To: <1450844609-9194-1-git-send-email-serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: adityakali-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lxc-devel-cunTk1MwBs9qMoObBWhMNEqPaTDuhLve2LY78lusg7I@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, "Serge E. Hallyn" From: Aditya Kali 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 Signed-off-by: Serge E. Hallyn --- kernel/cgroup.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 72336f5..e85fbf9 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -5925,10 +5925,28 @@ err_out: return ERR_PTR(err); } -static int cgroupns_install(struct nsproxy *nsproxy, void *ns) +static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) { - pr_info("setns not supported for cgroup namespace"); - return -EINVAL; + return container_of(ns, struct cgroup_namespace, ns); +} + +static int cgroupns_install(struct nsproxy *nsproxy, struct ns_common *ns) +{ + struct cgroup_namespace *cgroup_ns = to_cg_ns(ns); + + if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) || + !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN)) + return -EPERM; + + /* Don't need to do anything if we are attaching to our own cgroupns. */ + if (cgroup_ns == nsproxy->cgroup_ns) + return 0; + + get_cgroup_ns(cgroup_ns); + put_cgroup_ns(nsproxy->cgroup_ns); + nsproxy->cgroup_ns = cgroup_ns; + + return 0; } static struct ns_common *cgroupns_get(struct task_struct *task) -- 1.7.9.5