CVE-2026-68429

Full vulnerability record from the local CVENow database.

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.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-08-12 00:17:42.940000

Last modified

2026-11-06 17:19:33.053000

View original CVE JSON

{
  "id": "CVE-2026-68429",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-12T00:17:42.940",
  "lastModified": "2026-11-06T17:19:33.053",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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->mst_state = false and mgr->mst_primary = NULL) concurrently\nwith a caller invoking drm_dp_mst_topology_queue_probe(). Since the check\nis already performed under mgr->lock, 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->mst_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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/gpu/drm/display/drm_dp_mst_topology.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5f57a96e92c60f62da91d58ceb5e5acd40e7d594",
              "lessThan": "b1d05cc61dfa6c4bd5e67855bec6a03e955f512d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dbaeef363ea54f4c18112874b77503c72ba60fec",
              "lessThan": "4ed6d08c4a59ee6a8cb806347f6d9873de5d229e",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dbaeef363ea54f4c18112874b77503c72ba60fec",
              "lessThan": "8c6d84a54823cd839e6ce22af559925f1320c310",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dbaeef363ea54f4c18112874b77503c72ba60fec",
              "lessThan": "afdff9103818656627920c21822e48a6dae2906f",
              "versionType": "git",
              "status": "affected"
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            {
              "version": "dbaeef363ea54f4c18112874b77503c72ba60fec",
              "lessThan": "613059875958e7b217b250ed14c3b189f9488421",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6.6.86",
              "lessThan": "6.6.148",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/gpu/drm/display/drm_dp_mst_topology.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.12",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.12",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.148",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.101",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.42",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.6",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-11-06T16:49:22.194487Z",
          "id": "CVE-2026-68429",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/4ed6d08c4a59ee6a8cb806347f6d9873de5d229e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/613059875958e7b217b250ed14c3b189f9488421",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8c6d84a54823cd839e6ce22af559925f1320c310",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/afdff9103818656627920c21822e48a6dae2906f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b1d05cc61dfa6c4bd5e67855bec6a03e955f512d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
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}