CVE-2023-54258

A flaw was found in the Linux kernel's Common Internet File System (CIFS) client. A race condition can occur when the system handles file closes and network lease breaks simultaneously with an unmount operation. This timing issue can lead to a kernel crash, resulting in a Denial of Service (DoS) for the affected system. While a remote server can influence this, local system conditions are also required to trigger the vulnerability.

A race in the CIFS client oplock break worker can lead to a kernel oops when deferred close and lease break handling overlap with an unmount that tears down the session and server pointers. This happens because cifs_oplock_break may attempt to issue an oplock_response while the tree disconnect path is concurrently invalidating tcon ses and server state. The issue can be influenced by a remote SMB server that sends lease break events but it is not a pure network only attack because the race requires local teardown timing. Impact is denial of service via kernel crash.

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.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.