Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1448013

[PATCH v2 08/10] cgroupns: Add a limit on the number of cgroup namespaces

Show all headers | View raw

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 include/linux/user_namespace.h |  1 +
 kernel/cgroup.c                | 15 +++++++++++++++
 kernel/user_namespace.c        |  1 +
 3 files changed, 17 insertions(+)

diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 367cf08ff63d..1a3a9cb93277 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -27,6 +27,7 @@ enum ucounts {
 	UCOUNT_PID_NAMESPACES,
 	UCOUNT_UTS_NAMESPACES,
 	UCOUNT_IPC_NAMESPACES,
+	UCOUNT_CGROUP_NAMESPACES,
 	UCOUNT_COUNTS,
 };
 
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 86cb5c6e8932..240eec43390b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -6260,6 +6260,16 @@ void cgroup_sk_free(struct sock_cgroup_data *skcd)
 
 /* cgroup namespaces */
 
+static bool inc_cgroup_namespaces(struct user_namespace *ns)
+{
+	return inc_ucount(ns, UCOUNT_CGROUP_NAMESPACES);
+}
+
+static void dec_cgroup_namespaces(struct user_namespace *ns)
+{
+	dec_ucount(ns, UCOUNT_CGROUP_NAMESPACES);
+}
+
 static struct cgroup_namespace *alloc_cgroup_ns(void)
 {
 	struct cgroup_namespace *new_ns;
@@ -6281,6 +6291,7 @@ static struct cgroup_namespace *alloc_cgroup_ns(void)
 void free_cgroup_ns(struct cgroup_namespace *ns)
 {
 	put_css_set(ns->root_cset);
+	dec_cgroup_namespaces(ns->user_ns);
 	put_user_ns(ns->user_ns);
 	ns_free_inum(&ns->ns);
 	kfree(ns);
@@ -6305,6 +6316,9 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
 	if (!ns_capable(user_ns, CAP_SYS_ADMIN))
 		return ERR_PTR(-EPERM);
 
+	if (!inc_cgroup_namespaces(user_ns))
+		return ERR_PTR(-ENFILE);
+
 	mutex_lock(&cgroup_mutex);
 	spin_lock_bh(&css_set_lock);
 
@@ -6317,6 +6331,7 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
 	new_ns = alloc_cgroup_ns();
 	if (IS_ERR(new_ns)) {
 		put_css_set(cset);
+		dec_cgroup_namespaces(user_ns);
 		return new_ns;
 	}
 
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 060d3e099f87..1cf074cb47e2 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -80,6 +80,7 @@ static struct ctl_table userns_table[] = {
 	UCOUNT_ENTRY("max_pid_namespaces"),
 	UCOUNT_ENTRY("max_uts_namespaces"),
 	UCOUNT_ENTRY("max_ipc_namespaces"),
+	UCOUNT_ENTRY("max_cgroup_namespaces"),
 	{ }
 };
 #endif /* CONFIG_SYSCTL */
-- 
2.8.3

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v2 00/10] userns: sysctl limits for namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-21 19:00 +0200
  [PATCH v2 08/10] cgroupns: Add a limit on the number of cgroup namespaces "Eric W. Biederman" <ebiederm@xmission.com> - 2016-07-21 19:00 +0200
  [PATCH v2 10/10] mntns: Add a limit on the number of mount namespaces. "Eric W. Biederman" <ebiederm@xmission.com> - 2016-07-21 19:00 +0200
  [PATCH v2 07/10] ipcns: Add a  limit on the number of ipc namespaces "Eric W. Biederman" <ebiederm@xmission.com> - 2016-07-21 19:00 +0200
  [PATCH v2 01/10] sysctl: Stop implicitly passing current into sysctl_table_root.lookup "Eric W. Biederman" <ebiederm@xmission.com> - 2016-07-21 19:00 +0200
    [PATCH v2 03/10] userns: Add a limit on the number of user namespaces "Eric W. Biederman" <ebiederm@xmission.com> - 2016-07-21 19:00 +0200
  Re: [PATCH v2 00/10] userns: sysctl limits for namespaces Colin Walters <walters@verbum.org> - 2016-07-22 15:40 +0200
    Re: [PATCH v2 00/10] userns: sysctl limits for namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-22 21:00 +0200
      Re: [PATCH v2 00/10] userns: sysctl limits for namespaces Kees Cook <keescook@chromium.org> - 2016-07-22 23:50 +0200
        Re: [PATCH v2 00/10] userns: sysctl limits for namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-23 04:30 +0200

csiph-web