CVE-2026-23205

A memory leak flaw was found in the Linux kernel's CIFS/SMB client. In the smb2_open_file() function, request buffers are not properly freed when performing direct I/O writes to a read-only SMB share. This causes slab cache objects to remain allocated, which can prevent the cifs module from unloading cleanly and lead to gradual memory exhaustion with repeated operations.

Exploitation requires mounting an SMB share and performing specific I/O patterns (direct writes to read-only exports). The memory leak manifests primarily when unloading the cifs module, making it a reliability issue rather than a readily exploitable denial of service condition.

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.

To mitigate this issue, prevent the cifs module from being loaded. See https://access.redhat.com/solutions/41278 for instructions on how to blacklist kernel modules.