CVE-2026-68156

A flaw was found in the libceph component of the Linux kernel. During an authorizer update, if the authorizer is rebuilt, a stale pointer to a freed memory region can be retained. A remote attacker could exploit this by triggering a specific network reconnection, leading to a use-after-free vulnerability. This memory corruption could result in a system crash or denial of service.

This use-after-free flaw in the Linux kernel's libceph module can be triggered during Ceph client reconnection. An attacker could exploit this by manipulating Ceph authentication, potentially leading to a system crash or privilege escalation. The impact is significant due to the kernel context, but requires specific Ceph client usage.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, prevent the ceph kernel module from loading if Ceph client functionality is not in use. Create a file /etc/modprobe.d/ceph.conf with install ceph /bin/true. If the module is currently loaded, unload it using rmmod ceph. A system reboot is required for the changes to take full effect and ensure the module is not reloaded. Unloading the ceph module will impact systems actively using Ceph client features.