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>

1 files changed, 3 insertions, 5 deletions

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 9a8a2b77b874..03102d978180 100644
--- 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);
 }