CVE-2026-89635

/// Technical description

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

ksmbd: only rebind the reopened file's own oplock on durable reconnect

ksmbd_reopen_durable_fd() walks the inode's m_op_list and rebinds every

detached oplock to the reconnecting session:

list_for_each_entry_rcu(op, &ci->m_op_list, op_entry,

lockdep_is_held(&ci->m_lock)) {

if (op->conn)

continue;

op->conn = ksmbd_conn_get(fp->conn);

op->sess = work->sess;

}

The only key is op->conn == NULL, which every detached durable handle on

that inode matches, not just the one owned by fp. When two sessions hold

durable handles on the same file and both disconnect, reconnecting one of

them adopts the other session's oplock: op->sess is overwritten with the

reconnecting session without taking a reference on it, while op->conn

pins the connection.

The sibling teardown path, session_fd_check(), keys on the identity of

the connection being torn down (op->conn == conn) rather than on shared

state, and so does not h

/// 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