CVE-2026-68429

/// Technical description

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

drm/dp_mst: Handle torn-down topology gracefully in drm_dp_mst_topology_queue_probe()

A hotplug or link-loss event can tear down the MST topology

(setting mgr->mst_state = false and mgr->mst_primary = NULL) concurrently

with a caller invoking drm_dp_mst_topology_queue_probe(). Since the check

is already performed under mgr->lock, the condition is not a programming

error but a valid race -- the topology was valid when the caller decided

to call this function, but was torn down before the lock was acquired.

Replace the drm_WARN_ON() with a graceful early return. This eliminates

spurious kernel warnings and the resulting compositor crashes observed

when connecting/disconnecting DP MST monitors, while keeping the correct

behavior of doing nothing when MST is not active. A drm_dbg_mst() trace

is added so the skipped probe remains observable under MST debug logging.

The existing WARN_ON(mgr->mst_primary) in drm_dp_mst_to

/// 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