CVE-2026-68429
Received Received - Intake

Race Condition in Linux Kernel DRM DP MST Topology Handling

Publication date: 2026-08-12

Last updated on: 2026-08-12

Assigner: kernel.org

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_topology_mgr_set_mst() already catches the case where the topology is initialized twice, so no diagnostic coverage is lost.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-12
Last Modified
2026-08-12
Generated
2026-08-12
AI Q&A
2026-08-12
EPSS Evaluated
N/A
NVD
CVE-2026-68429
EUVD
EUVD-2026-57037

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability in the Linux kernel involves a race condition in the DisplayPort Multi-Stream Transport (MST) topology management. A hotplug or link-loss event can tear down the MST topology while a function called drm_dp_mst_topology_queue_probe() is being executed. This creates a valid race condition where the topology was valid when the function was called but torn down before the lock was acquired, leading to spurious kernel warnings and compositor crashes when connecting or disconnecting DP MST monitors.

Detection Guidance

This vulnerability is specific to the Linux kernel's DRM subsystem and relates to DisplayPort MST (Multi-Stream Transport) topology handling. Detection requires checking kernel logs for related warnings or crashes during DP MST monitor connections or disconnections. Monitor logs for messages about drm_dp_mst_topology_queue_probe or compositor crashes.

Impact Analysis

This vulnerability can cause system instability, such as kernel warnings and crashes in the display compositor, when connecting or disconnecting DisplayPort MST monitors. Users may experience unexpected crashes or graphical issues during these operations.

Mitigation Strategies

Update your Linux kernel to the latest stable version that includes the fix for this issue. If updating is not immediately possible, avoid using DisplayPort MST monitors until the kernel is updated to prevent potential crashes.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-68429. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart