1 files changed, 38 insertions, 29 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 5d0b477c2682..12852363d90e 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1715,18 +1715,14 @@ static inline bool may_mount(void)
 	return ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN);
 }
 
-#ifdef	CONFIG_MANDATORY_FILE_LOCKING
-static inline bool may_mandlock(void)
+static void warn_mandlock(void)
 {
-	return capable(CAP_SYS_ADMIN);
+	pr_warn_once("=======================================================\n"
+		     "WARNING: The mand mount option has been deprecated and\n"
+		     "         and is ignored by this kernel. Remove the mand\n"
+		     "         option from the mount to silence this warning.\n"
+		     "=======================================================\n");
 }
-#else
-static inline bool may_mandlock(void)
-{
-	pr_warn("VFS: \"mand\" mount option not supported");
-	return false;
-}
-#endif
 
 static int can_umount(const struct path *path, int flags)
 {
@@ -1938,6 +1934,20 @@ void drop_collected_mounts(struct vfsmount *mnt)
 	namespace_unlock();
 }
 
+static bool has_locked_children(struct mount *mnt, struct dentry *dentry)
+{
+	struct mount *child;
+
+	list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) {
+		if (!is_subdir(child->mnt_mountpoint, dentry))
+			continue;
+
+		if (child->mnt.mnt_flags & MNT_LOCKED)
+			return true;
+	}
+	return false;
+}
+
 /**
  * clone_private_mount - create a private clone of a path
  * @path: path to clone
@@ -1953,10 +1963,19 @@ struct vfsmount *clone_private_mount(const struct path *path)
 	struct mount *old_mnt = real_mount(path->mnt);
 	struct mount *new_mnt;
 
+	down_read(&namespace_sem);
 	if (IS_MNT_UNBINDABLE(old_mnt))
-		return ERR_PTR(-EINVAL);
+		goto invalid;
+
+	if (!check_mnt(old_mnt))
+		goto invalid;
+
+	if (has_locked_children(old_mnt, path->dentry))
+		goto invalid;
 
 	new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE);
+	up_read(&namespace_sem);
+
 	if (IS_ERR(new_mnt))
 		return ERR_CAST(new_mnt);
 
@@ -1964,6 +1983,10 @@ struct vfsmount *clone_private_mount(const struct path *path)
 	new_mnt->mnt_ns = MNT_NS_INTERNAL;
 
 	return &new_mnt->mnt;
+
+invalid:
+	up_read(&namespace_sem);
+	return ERR_PTR(-EINVAL);
 }
 EXPORT_SYMBOL_GPL(clone_private_mount);
 
@@ -2315,19 +2338,6 @@ static int do_change_type(struct path *path, int ms_flags)
 	return err;
 }
 
-static bool has_locked_children(struct mount *mnt, struct dentry *dentry)
-{
-	struct mount *child;
-	list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) {
-		if (!is_subdir(child->mnt_mountpoint, dentry))
-			continue;
-
-		if (child->mnt.mnt_flags & MNT_LOCKED)
-			return true;
-	}
-	return false;
-}
-
 static struct mount *__do_loopback(struct path *old_path, int recurse)
 {
 	struct mount *mnt = ERR_PTR(-EINVAL), *old = real_mount(old_path->mnt);
@@ -3251,8 +3261,8 @@ int path_mount(const char *dev_name, struct path *path,
 		return ret;
 	if (!may_mount())
 		return -EPERM;
-	if ((flags & SB_MANDLOCK) && !may_mandlock())
-		return -EPERM;
+	if (flags & SB_MANDLOCK)
+		warn_mandlock();
 
 	/* Default to relatime unless overriden */
 	if (!(flags & MS_NOATIME))
@@ -3635,9 +3645,8 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags,
 	if (fc->phase != FS_CONTEXT_AWAITING_MOUNT)
 		goto err_unlock;
 
-	ret = -EPERM;
-	if ((fc->sb_flags & SB_MANDLOCK) && !may_mandlock())
-		goto err_unlock;
+	if (fc->sb_flags & SB_MANDLOCK)
+		warn_mandlock();
 
 	newmount.mnt = vfs_create_mount(fc);
 	if (IS_ERR(newmount.mnt)) {