CVE-2024-53185

A flaw was found in the Linux kernel's SMB (Server Message Block) client. When mounting a share with encryption enabled under specific protocol options, the client fails to properly initialize the cipher type, leaving cryptographic structures unallocated. An authorized local user can exploit this vulnerability to trigger a NULL pointer dereference during encryption setup, resulting in a system crash and 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.

To mitigate this issue, avoid mounting SMB network shares using SMB version 3.02 with encryption enabled (for example, by omitting the 'seal' mount option or by selecting a newer protocol dialect such as 'vers=3.1.1').

Alternatively, if SMB/CIFS file shares are not required in the environment, prevent the CIFS kernel module from loading:

1. Blacklist the module configuration:

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

2. Unload the module if not currently in use:

modprobe -r cifs

Caveats: Disabling the CIFS kernel module will prevent the system from accessing all SMB and CIFS remote shares. If the module is currently loaded into the running kernel or used by active mounts, a system restart is required for the change to take effect.