Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html