apparmor: sysctl to enable unprivileged user ns AppArmor policy loading

[linux.git] / security / apparmor / lsm.c

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index b1def70b94f1ebc3d9a70fa1f5572698c4dac22c..8a887c392fdb4e8879945a9a8f7768fbac065e0b 100644 (file)
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -868,6 +868,46 @@ static int __init set_init_ctx(void)
        return 0;
 }
 
+#ifdef CONFIG_SYSCTL
+static int apparmor_dointvec(struct ctl_table *table, int write,
+                            void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       if (!policy_admin_capable(NULL))
+               return -EPERM;
+       if (!apparmor_enabled)
+               return -EINVAL;
+
+       return proc_dointvec(table, write, buffer, lenp, ppos);
+}
+
+static struct ctl_path apparmor_sysctl_path[] = {
+       { .procname = "kernel", },
+       { }
+};
+
+static struct ctl_table apparmor_sysctl_table[] = {
+       {
+               .procname       = "unprivileged_userns_apparmor_policy",
+               .data           = &unprivileged_userns_apparmor_policy,
+               .maxlen         = sizeof(int),
+               .mode           = 0600,
+               .proc_handler   = apparmor_dointvec,
+       },
+       { }
+};
+
+static int __init apparmor_init_sysctl(void)
+{
+       return register_sysctl_paths(apparmor_sysctl_path,
+                                    apparmor_sysctl_table) ? 0 : -ENOMEM;
+}
+#else
+static inline int apparmor_init_sysctl(void)
+{
+       return 0;
+}
+#endif /* CONFIG_SYSCTL */
+
 static int __init apparmor_init(void)
 {
        int error;
@@ -890,6 +930,13 @@ static int __init apparmor_init(void)
                goto alloc_out;
        }
 
+       error = apparmor_init_sysctl();
+       if (error) {
+               AA_ERROR("Unable to register sysctls\n");
+               goto alloc_out;
+
+       }
+
        error = set_init_ctx();
        if (error) {
                AA_ERROR("Failed to set context on init task\n");