• Eric W. Biederman's avatar
    umount: Disallow unprivileged mount force · b2f5d4dc
    Eric W. Biederman authored
    Forced unmount affects not just the mount namespace but the underlying
    superblock as well.  Restrict forced unmount to the global root user
    for now.  Otherwise it becomes possible a user in a less privileged
    mount namespace to force the shutdown of a superblock of a filesystem
    in a more privileged mount namespace, allowing a DOS attack on root.
    
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    b2f5d4dc
namespace.c 78.1 KB