CVE-2026-68155

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> libceph: Reject monmaps advertising zero monitors<br /> <br /> A message of type CEPH_MSG_MON_MAP contains a monmap that is sent from a<br /> monitor to the client. This monmap contains information about the<br /> existing monitors in the cluster. Currently, a monmap indicating that<br /> there are zero monitors in the cluster is treated as valid. However, it<br /> is impossible to have zero monitors in the cluster and still receive a<br /> valid monmap from a monitor. Therefore, such a monmap must be corrupted<br /> and should be treated as invalid. Furthermore, a monmap with a monitor<br /> count of zero can subsequently crash the client when attempting to open<br /> a session with a monitor in __open_session(). This happens because the<br /> "BUG_ON(monc-&gt;monmap-&gt;num_mon CEPH_MAX_MON.<br /> <br /> [ idryomov: drop "log output for unusual values of num_mon" part ]