CVE-2026-80926

/// Technical description

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

ksmbd: fix use-after-free in oplock break notification

smb2_oplock_break_noti() reads opinfo->conn without any lock and

dereferences it after two allocations which may sleep. When the

durable handle owning the oplock is disconnected, session_fd_check()

clears opinfo->conn and drops its conn reference under ci->m_lock, and

the last ksmbd_conn_put() frees the connection. A break triggered by

another connection that races with the teardown can then resurrect the

freed connection: ksmbd_conn_get() is a plain atomic_inc, and the

queued break work later dereferences the stale conn via

ksmbd_conn_write(), a use-after-free reachable by any authenticated

client holding a durable batch oplock.

Thread the caller's inode into the notification path instead of taking

a new reference on it. Every caller of oplock_break() already holds a

live ksmbd_file (or an explicit ksmbd_inode_lookup_lock() reference,

in the parent lease bre

/// 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