Linux Kernel ksmbd CVE-2026-43376

Upgrade to patched Linux kernel versions: 6.6.130+ for 6.6.x series, 6.12.78+ for 6.12.x series, 6.18.19+ for 6.18.x series, 6.19.9+ for 6.19.x series, or 7.0+ for mainline. Verify patch integration by checking for commits 302fef75512b, 08aa9f3c8cf4, 1d6abf145615, ce8507ee82c8, or 1dfd062caa16 in kernel changelogs available at https://git.kernel.org/stable/. Distribution users should apply security updates through package managers (apt, dnf, zypper) when vendors release patched kernel packages. If immediate patching is unfeasible, disable ksmbd module entirely via 'rmmod ksmbd' and block autoloading with 'echo "install ksmbd /bin/true" > /etc/modprobe.d/disable-ksmbd.conf', then restart. This mitigation eliminates attack surface but breaks SMB server functionality - acceptable for systems not requiring kernel-mode SMB sharing. Alternative: restrict ksmbd network access via firewall rules (block ports 445, 139) to trusted management networks only, reducing exposure to remote attacks while maintaining local functionality. This partial mitigation does not address privilege escalation risk from local authenticated users. Do not rely on ksmbd access controls alone, as race condition occurs before authentication layer.