CVE-2026-99118

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

drm/i915/dmc: Harden DMC firmware payload parsing

Validate the conversion of the DMC firmware size from dwords to bytes using check mul overflow() before calculating the firmware payload size.

Reject zero-length payloads and zero MMIO counts in the DMC firmware header so malformed firmware is caught early. Also set dmc fw size only after the payload allocation succeeds.

(cherry picked from commit efde6601a1f1daedfe3dcc2816c934ddb44e3eef)