CVE-2026-43215

A flaw was found in the Linux kernel's Common Internet File System (CIFS) implementation. Incorrect locking mechanisms were used for tcon fields, where the cifs_tcp_ses_lock was applied too broadly instead of more granular locks. This improper locking could lead to concurrency issues within the kernel, potentially resulting in system instability or a denial of service (DoS).

Red Hat acknowledges the upstream Linux kernel correction for «cifs» as described in COMMENT_ZERO. Fixes are delivered through standard kernel errata for supported products. Operational exposure depends on whether this subsystem or driver is active in your configuration.

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.