GHSA-47QH-XGQX-2FV5
Vulnerability from github – Published: 2026-08-12 00:31 – Updated: 2026-08-12 00:31In 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.
{
"affected": [],
"aliases": [
"CVE-2026-68429"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-12T00:17:42Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp_mst: Handle torn-down topology gracefully in drm_dp_mst_topology_queue_probe()\n\nA hotplug or link-loss event can tear down the MST topology\n(setting mgr-\u003emst_state = false and mgr-\u003emst_primary = NULL) concurrently\nwith a caller invoking drm_dp_mst_topology_queue_probe(). Since the check\nis already performed under mgr-\u003elock, the condition is not a programming\nerror but a valid race -- the topology was valid when the caller decided\nto call this function, but was torn down before the lock was acquired.\n\nReplace the drm_WARN_ON() with a graceful early return. This eliminates\nspurious kernel warnings and the resulting compositor crashes observed\nwhen connecting/disconnecting DP MST monitors, while keeping the correct\nbehavior of doing nothing when MST is not active. A drm_dbg_mst() trace\nis added so the skipped probe remains observable under MST debug logging.\n\nThe existing WARN_ON(mgr-\u003emst_primary) in drm_dp_mst_topology_mgr_set_mst()\nalready catches the case where the topology is initialized twice, so no\ndiagnostic coverage is lost.",
"id": "GHSA-47qh-xgqx-2fv5",
"modified": "2026-08-12T00:31:12Z",
"published": "2026-08-12T00:31:12Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68429"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4ed6d08c4a59ee6a8cb806347f6d9873de5d229e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/613059875958e7b217b250ed14c3b189f9488421"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8c6d84a54823cd839e6ce22af559925f1320c310"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/afdff9103818656627920c21822e48a6dae2906f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b1d05cc61dfa6c4bd5e67855bec6a03e955f512d"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.