CVE-2024-53176

A flaw was found in the Linux kernel's SMB/CIFS client. A race condition can occur during unmount operations when closing cached directories while concurrent background directory cleanup or server reconnection tasks are underway. This timing error prevents cached directory entries from being released properly, triggering a kernel crash. An authorized local user can trigger this issue during share unmount operations, resulting in a Denial of Service (DoS).

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.

Prevent loading of the cifs kernel module if SMB/CIFS network file systems are not required.

1. Blacklist the kernel module by creating a configuration file:

echo "install cifs /bin/true" > /etc/modprobe.d/disable-cifs.conf

2. If the module is currently loaded and no SMB shares are mounted, unload it:

rmmod cifs

Caveats: Disabling this module prevents the system from mounting or accessing CIFS/SMB network shares.

Warning: If CIFS shares are currently mounted or the module is actively in use, a system reboot is required for this change to take full effect.