GHSA-793Q-4MV8-RVWH
Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-14 00:31In the Linux kernel, the following vulnerability has been resolved:
ALSA: timer: drain a slave's callback before its master detaches it
snd_timer_close_locked() drains the closing instance's own in-flight callback (IFLG_CALLBACK) before freeing it, but not its slaves'. When a master instance is closed, remove_slave_links() clears each slave's ->timer; the slave's own close then reads timer == NULL and takes the branch that skips the drain entirely (snd_timer_stop_slave() also no-ops on a NULL timer). So a slave whose callback is still running when the master is closed is freed underneath the live callback, leading to use-after-free.
Drain the slaves too before remove_slave_links() severs them. snd_timer_stop() has already taken this instance off the active list, so no new slave callback can be queued. Take the slaves off the ack list so a pending one can't fire either, then wait for any that is already in flight.
{
"affected": [],
"aliases": [
"CVE-2026-68201"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-10T13:20:07Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: timer: drain a slave\u0027s callback before its master detaches it\n\nsnd_timer_close_locked() drains the closing instance\u0027s own in-flight\ncallback (IFLG_CALLBACK) before freeing it, but not its slaves\u0027. When a\nmaster instance is closed, remove_slave_links() clears each slave\u0027s\n-\u003etimer; the slave\u0027s own close then reads timer == NULL and takes the\nbranch that skips the drain entirely (snd_timer_stop_slave() also no-ops\non a NULL timer). So a slave whose callback is still running when the\nmaster is closed is freed underneath the live callback, leading to\nuse-after-free.\n\nDrain the slaves too before remove_slave_links() severs them.\nsnd_timer_stop() has already taken this instance off the active list, so\nno new slave callback can be queued. Take the slaves off the ack list so\na pending one can\u0027t fire either, then wait for any that is already in\nflight.",
"id": "GHSA-793q-4mv8-rvwh",
"modified": "2026-08-14T00:31:53Z",
"published": "2026-08-10T15:33:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68201"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2b298997786876b225cff2446e11a0fa6f602f6d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/426c0ff1c433d6030610ad4f9375746dfe931caa"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bdefe1346a8e6b8dc8593406dc2617e985fcbcab"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- 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.