procfs: fix a vfsmount longterm reference leak

kern_mount() doesn't pair with plain mntput()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 9a8a2b77b87479621838ee00c928a43edbe938e9..03102d978180eba68469ef01d13ad25465f5b796 100644 (file)
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -91,20 +91,18 @@ static struct file_system_type proc_fs_type = {
 
 void __init proc_root_init(void)
 {
-       struct vfsmount *mnt;
        int err;
 
        proc_init_inodecache();
        err = register_filesystem(&proc_fs_type);
        if (err)
                return;
-       mnt = kern_mount_data(&proc_fs_type, &init_pid_ns);
-       if (IS_ERR(mnt)) {
+       err = pid_ns_prepare_proc(&init_pid_ns);
+       if (err) {
                unregister_filesystem(&proc_fs_type);
                return;
        }
 
-       init_pid_ns.proc_mnt = mnt;
        proc_symlink("mounts", NULL, "self/mounts");
 
        proc_net_init();
@@ -209,5 +207,5 @@ int pid_ns_prepare_proc(struct pid_namespace *ns)
 
 void pid_ns_release_proc(struct pid_namespace *ns)
 {
-       mntput(ns->proc_mnt);
+       kern_unmount(ns->proc_mnt);
 }