userns: Restrict when proc and sysfs can be mounted

[~andy/linux] / fs / proc / root.c

diff --git a/fs/proc/root.c b/fs/proc/root.c
index c6e9fac26bace4e9b63bd57dce624589dc67dfd7..9c7fab1d23f0d17d68446bf3d46ce1a906ae0907 100644 (file)
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -16,6 +16,7 @@
 #include <linux/sched.h>
 #include <linux/module.h>
 #include <linux/bitops.h>
+#include <linux/user_namespace.h>
 #include <linux/mount.h>
 #include <linux/pid_namespace.h>
 #include <linux/parser.h>
@@ -108,6 +109,9 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
        } else {
                ns = task_active_pid_ns(current);
                options = data;
+
+               if (!current_user_ns()->may_mount_proc)
+                       return ERR_PTR(-EPERM);
        }
 
        sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns);