GHSA-42J7-3823-X574
Vulnerability from github – Published: 2026-09-04 18:31 – Updated: 2026-09-04 18:31In the Linux kernel, the following vulnerability has been resolved:
ALSA: FCP: Use a private URB for the notification endpoint
fcp_init_notify() used mixer->urb, which snd_usb_mixer_status_create() allocates for the optional UAC2 status interrupt endpoint and mixer.c kills, resubmits and frees. On a device with that endpoint, fcp_init_notify()'s "already set up" early return fires on the status URB and returns success without doing anything. No FCP notification URB is submitted, and cmd_done is left zeroed because it is initialised past that early return and nowhere else. fcp_init() then issues init1_opcode and wait_for_completion_timeout() would crash adding to the zeroed wait.head. fcp_cleanup_urb() would also kill and free mixer.c's status URB.
Use a separate URB in fcp_data, and initialise cmd_done in fcp_init_private() where fcp_data is allocated. fcp_init_notify() is reached again after suspend via fcp_reinit(), and the URB kill path in fcp_notify() completes cmd_done, leaving a stale count that would satisfy the next command's wait before the device ACKs. Use reinit_completion() to clear it.
{
"affected": [],
"aliases": [
"CVE-2026-80816"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-04T16:18:09Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: FCP: Use a private URB for the notification endpoint\n\nfcp_init_notify() used mixer-\u003eurb, which snd_usb_mixer_status_create()\nallocates for the optional UAC2 status interrupt endpoint and mixer.c\nkills, resubmits and frees. On a device with that endpoint,\nfcp_init_notify()\u0027s \"already set up\" early return fires on the status\nURB and returns success without doing anything. No FCP notification\nURB is submitted, and cmd_done is left zeroed because it is\ninitialised past that early return and nowhere else. fcp_init() then\nissues init1_opcode and wait_for_completion_timeout() would crash\nadding to the zeroed wait.head. fcp_cleanup_urb() would also kill and\nfree mixer.c\u0027s status URB.\n\nUse a separate URB in fcp_data, and initialise cmd_done in\nfcp_init_private() where fcp_data is allocated. fcp_init_notify() is\nreached again after suspend via fcp_reinit(), and the URB kill path in\nfcp_notify() completes cmd_done, leaving a stale count that would\nsatisfy the next command\u0027s wait before the device ACKs. Use\nreinit_completion() to clear it.",
"id": "GHSA-42j7-3823-x574",
"modified": "2026-09-04T18:31:27Z",
"published": "2026-09-04T18:31:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80816"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5da21a434171e8ecf1d992c6f1d84c0c706fd395"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/65aceb45ca91ddb7f7ed178821f481b34da35543"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6db3c1d7e2872c9904e05ca8e0515920776a3c9c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/918b8d231c571c50a00efe92ffc8404a537a0490"
}
],
"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.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- 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.