Affected: Linux

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

drm/i915/mst: limit DP MST ESI service loop

The loop in intel_dp_check_mst_status() keeps servicing interrupts originating from the sink without bound. Add an upper bound to the new interrupts occurring during interrupt processing to not get stuck on potentially stuck sink devices. Use arbitrary 32 tries to clear incoming interrupts in one go.

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

Note: The condition likely pre-dates the commit in the Fixes: tag, but this is about as far back as a backport has any chance of succeeding. Before that, the retry had a goto.

(cherry picked from commit b4ea5272133059acb493cc36599071a9e852ec2e)