CVE-2026-90167

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the ksmbd module where the close operation may abort an in-flight oplock break while another breaker holds an opinfo reference. Due to a lack of serialization during the close transition and bit acquisition, a waiter can become a new break owner via the test and set bit() fast path. This allows the OPLOCK CLOSING state to be overwritten with OPLOCK ACK WAIT, causing a break to continue for a dying opinfo. Oplock (Opportunistic Lock) is a mechanism used in SMB to reduce network traffic by allowing clients to cache data locally.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.