CVE-2026-68253

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

drm/i915/hdcp: check streams[] bounds before overflow

The data->streams[] overflow check is done after the buffer overflow has
already happened. Move the overflow check before the write.

Side note, emitting a warning splat with a backtrace might be overkill
here, but prefer not changing the behaviour other than not doing the
overrun.

Discovered using AI-assisted static analysis confirmed by Intel Product
Security.

(cherry picked from commit 9284ab3b6e776c315883ac2611283d263c9460fd)