CVE-2026-68156

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

libceph: refresh auth->authorizer_buf{,_len} after authorizer update

ceph_x_create_authorizer() caches au->buf->vec.iov_base and

au->buf->vec.iov_len in struct ceph_auth_handshake. These

cached values are then used by the messenger connect code when

sending the authorizer.

ceph_x_update_authorizer() can rebuild the authorizer when a newer

service ticket is available. If the rebuilt authorizer no longer

fits in the existing buffer, ceph_x_build_authorizer() drops its

reference to au->buf and allocates a new one. If this is the final

reference, ceph_buffer_put() frees the old ceph_buffer and its

vec.iov_base, but auth->authorizer_buf still points at that freed

memory.

A subsequent msgr1 reconnect can therefore queue the stale pointer

and trigger a KASAN slab-use-after-free in _copy_from_iter() while

tcp_sendmsg() copies the authorizer.

Refresh auth->authorizer_buf and auth->authorizer_buf_len after a

successful a

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References