Merge tag 'backport/v3.14.24-ltsi-rc1/rcar-snd-to-next-20141121' into backport/v3...

[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 75536db..d9bf3ef 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1365,6 +1365,8 @@ static int do_umount(struct mount *mnt, int flags)
                 * Special case for "unmounting" root ...
                 * we just try to remount it readonly.
                 */
+               if (!capable(CAP_SYS_ADMIN))
+                       return -EPERM;
                down_write(&sb->s_umount);
                if (!(sb->s_flags & MS_RDONLY))
                        retval = do_remount_sb(sb, MS_RDONLY, NULL, 0);
@@ -2829,6 +2831,9 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
        /* make sure we can reach put_old from new_root */
        if (!is_path_reachable(old_mnt, old.dentry, &new))
                goto out4;
+       /* make certain new is below the root */
+       if (!is_path_reachable(new_mnt, new.dentry, &root))
+               goto out4;
        root_mp->m_count++; /* pin it so it won't go away */
        lock_mount_hash();
        detach_mnt(new_mnt, &parent_path);