CVE-2026-74673

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

Input: evdev - fix information leak in evdev_pass_values()

In evdev_pass_values(), the input_event structure is allocated on the

kernel stack and populated field-by-field. However, it is never fully

initialized. On architectures where struct input_event contains explicit

or implicit padding (such as the 32-bit __pad field on SPARC64), these

padding bytes are left uninitialized.

When this event structure is subsequently passed to the client buffer

and later copied to userspace, the uninitialized padding bytes leak

kernel stack memory, potentially exposing sensitive information.

Similar issues exist in __evdev_queue_syn_dropped and __pass_event.

Fix this by explicitly zeroing the entire event structure with memset()

before populating its fields. This ensures all padding bytes are cleared

before the data crosses the security boundary.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References