GHSA-23XC-5VXV-WJ6V
Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-10 15:33In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: dce100: skip non-DP stream encoders for DP MST
On DCE8-class ASICs (e.g. Bonaire), the resource pool contains digital DIG stream encoders plus one analog DAC encoder. When assigning a stream encoder for a second DisplayPort MST stream, if the preferred digital encoder is already acquired, dce100_find_first_free_match_stream_enc_for_link() falls back to the first free pool entry. That entry may be the analog encoder, whose funcs table lacks DP hooks such as dp_set_stream_attribute. The subsequent atomic commit then dereferences NULL function pointers in link_set_dpms_on() and crashes.
Skip encoders without dp_set_stream_attribute when the stream uses a DP signal (including MST). Use dc_is_dp_signal(stream->signal) for the MST fallback path instead of checking only the link connector signal.
Tested on: - GPU: AMD Radeon R7 260X (Bonaire / DCE8) - Board: Supermicro C9X299-PG300 - Setup: DP MST daisy chain, hotplug second monitor or have it connected on boot - Kernel: 7.1.3 (issue observed since 6.19) - Result: kernel oops without patch; dual monitors stable with patch
(cherry picked from commit 28ec64943e3ee4d9b8d30cea61e380f1429953a8)
{
"affected": [],
"aliases": [
"CVE-2026-68235"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-10T13:20:11Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: dce100: skip non-DP stream encoders for DP MST\n\nOn DCE8-class ASICs (e.g. Bonaire), the resource pool contains digital\nDIG stream encoders plus one analog DAC encoder. When assigning a stream\nencoder for a second DisplayPort MST stream, if the preferred digital\nencoder is already acquired, dce100_find_first_free_match_stream_enc_for_link()\nfalls back to the first free pool entry. That entry may be the analog\nencoder, whose funcs table lacks DP hooks such as dp_set_stream_attribute.\nThe subsequent atomic commit then dereferences NULL function pointers in\nlink_set_dpms_on() and crashes.\n\nSkip encoders without dp_set_stream_attribute when the stream uses a DP\nsignal (including MST). Use dc_is_dp_signal(stream-\u003esignal) for the MST\nfallback path instead of checking only the link connector signal.\n\nTested on:\n- GPU: AMD Radeon R7 260X (Bonaire / DCE8)\n- Board: Supermicro C9X299-PG300\n- Setup: DP MST daisy chain, hotplug second monitor or have it connected on boot\n- Kernel: 7.1.3 (issue observed since 6.19)\n- Result: kernel oops without patch; dual monitors stable with patch\n\n(cherry picked from commit 28ec64943e3ee4d9b8d30cea61e380f1429953a8)",
"id": "GHSA-23xc-5vxv-wj6v",
"modified": "2026-08-10T15:33:42Z",
"published": "2026-08-10T15:33:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68235"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/51ea665c30c424c98959101f3bf6f48ab42949c8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bfe28ce019c2d667d98071262da33d8bba122919"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d340cba0df4cf327c7e89c7c1a4e79d4771d7dd5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ed2d86aef9fa4c43f82da0fca91a60f7326d7d03"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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Nomenclature
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- 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.