userns: Allow unprivilged mounts of proc and sysfs

- The context in which proc and sysfs are mounted have no
  effect on the the uid/gid of their files so no conversion is
  needed except allowing the mount.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

diff --git a/fs/proc/root.c b/fs/proc/root.c
index f2f2511..c6e9fac 100644 (file)
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -145,6 +145,7 @@ static struct file_system_type proc_fs_type = {
        .name           = "proc",
        .mount          = proc_mount,
        .kill_sb        = proc_kill_sb,
+       .fs_flags       = FS_USERNS_MOUNT,
 };
 
 void __init proc_root_init(void)

diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 71eb7e2..db940a9 100644 (file)
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -149,6 +149,7 @@ static struct file_system_type sysfs_fs_type = {
        .name           = "sysfs",
        .mount          = sysfs_mount,
        .kill_sb        = sysfs_kill_sb,
+       .fs_flags       = FS_USERNS_MOUNT,
 };
 
 int __init sysfs_init(void)