The Linux kernel's vt subsystem contained a vulnerability where the KDSKBMETA ioctl could be used to modify the keyboard meta mode without proper permission checks. Unlike other keyboard setter ioctls in vt_k_ioctl(), KDSKBMETA did not enforce the !perm check, enabling a process to alter meta mode on a non-controlling console without authorization. This issue has been resolved by adding the missing permission check.

An unauthorized process could change the keyboard meta mode on a non-controlling console, potentially leading to unauthorized input behavior or interference with keyboard input handling. There is no indication of privilege escalation or code execution from the provided data.

A fix has been implemented in the Linux kernel by adding the missing permission check for the KDSKBMETA ioctl. Users should update their Linux kernel to the patched version once it is available. Patch status is not explicitly confirmed in the provided data; therefore, check the official Linux kernel advisories or vendor updates for the current remediation status.