ALSA: seq: Don't leak the extension cell pointer in the bounce payload
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Don't leak the extension cell pointer in the bounce payload The bounce_error_event() embeds the failed event in the bounce payload by pointing data.ext.ptr at it. When that event is a queued variable-length event, its own data.ext.ptr holds the address of its first extension cell, put there by snd_seq_event_dup(). The payload goes out verbatim through snd_seq_expand_var_event(), so the address reaches userspace. That is the same address commit 705dd6dcbc0e ("ALSA: seq: Clear variable event pointer on read") removed from the event header. The read path still clears it there, just above the call that expands the payload. Embed a sanitised copy instead, treated exactly as snd_seq_read() treats the header. A stack copy is enough because delivery is synchronous and snd_seq_event_dup() copies before returning. An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE, queueing a variable-length event to a port that does not exist and reading the bounce back. Eight bytes on 64-bit, from its own pool.
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 6.12.110, 6.18.52, 7.2.6
- CVEs
- CVE-2026-90220
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 04:31 UTC · Revision 1
Source evidence
ALSA: seq: Don't leak the extension cell pointer in the bounce payload
core-osv · Original sourcePublished 17 Sept 2026, 16:07 UTC
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Don't leak the extension cell pointer in the bounce payload The bounce_error_event() embeds the failed event in the bounce payload by pointing data.ext.ptr at it. When that event is a queued variable-length event, its own data.ext.ptr holds the address of its first extension cell, put there by snd_seq_event_dup(). The payload goes out verbatim through snd_seq_expand_var_event(), so the address reaches userspace. That is the same address commit 705dd6dcbc0e ("ALSA: seq: Clear variable event pointer on read") removed from the event header. The read path still clears it there, just above the call that expands the payload. Embed a sanitised copy instead, treated exactly as snd_seq_read() treats the header. A stack copy is enough because delivery is synchronous and snd_seq_event_dup() copies before returning. An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE, queueing a variable-length event to a port that does not exist and reading the bounce back. Eight bytes on 64-bit, from its own pool.
osv:CVE-2026-90220
Kernel
Fixed versions: 6.12.110, 6.18.52, 7.2.6
Complete source record
{
"id": "d402ae8a623f5d0c7170a49f2f11274777845fb9aa25cf9abf3f1858e82482bf",
"url": "https://osv.dev/vulnerability/CVE-2026-90220",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "ALSA: seq: Don't leak the extension cell pointer in the bounce payload",
"summary": "In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Don't leak the extension cell pointer in the bounce payload The bounce_error_event() embeds the failed event in the bounce payload by pointing data.ext.ptr at it. When that event is a queued variable-length event, its own data.ext.ptr holds the address of its first extension cell, put there by snd_seq_event_dup(). The payload goes out verbatim through snd_seq_expand_var_event(), so the address reaches userspace. That is the same address commit 705dd6dcbc0e (\"ALSA: seq: Clear variable event pointer on read\") removed from the event header. The read path still clears it there, just above the call that expands the payload. Embed a sanitised copy instead, treated exactly as snd_seq_read() treats the header. A stack copy is enough because delivery is synchronous and snd_seq_event_dup() copies before returning. An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE, queueing a variable-length event to a port that does not exist and reading the bounce back. Eight bytes on 64-bit, from its own pool.",
"evidence": "osv:CVE-2026-90220",
"products": [
{
"name": {
"value": "Kernel",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.12.110",
"evidence": "/affected/1/ranges"
},
{
"value": "6.18.52",
"evidence": "/affected/1/ranges"
},
{
"value": "7.2.6",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CVE-2026-90220",
"aliases": [
"CVE-2026-90220"
],
"affected": [
{
"ranges": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "05e2358fec8812c37516ccea63bc4b9956d864ba"
},
{
"fixed": "c92b2e6e418a3885758438dddcead6e954a9e095"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "93d260ce43a81df579c98bee92b91316df9c1c57"
},
{
"fixed": "42c3f856d13a91a0d4c302a0c6854813621136db"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "dae23c545eb5a2be3b27a82fd0f611894fb8ab69"
},
{
"fixed": "b1e8d40663997aacaa198f37ce6893e07aaba77a"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "efc86691e4d8083d9e380ea95042c2cf679f65fd"
},
{
"fixed": "6e6e471eef1d5d8cb056c7d364023fe048249204"
},
{
"fixed": "59e1592d3c270ff4642d5d6dc55c545306eb0693"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.12.97"
},
{
"fixed": "6.12.110"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.18.40"
},
{
"fixed": "6.18.52"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.6.160"
},
{
"fixed": "6.7"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "7.1.5"
},
{
"fixed": "7.2"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "eae296065ede41a24040e6a7c909ec970f78b4eb"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "0527a56cb327021cb73167cfddf0e49efa043500"
}
]
}
],
"versions": [
"v6.12.109",
"v6.12.108",
"v6.12.107",
"v6.12.106",
"v6.12.105",
"v6.12.104",
"v6.12.103",
"v6.12.102",
"v6.12.101",
"v6.12.100",
"v6.12.99",
"v6.12.98",
"v6.12.97",
"v6.18.51",
"v6.18.50",
"v6.18.49",
"v6.18.48",
"v6.18.47",
"v6.18.46",
"v6.18.45",
"v6.18.44",
"v6.18.43",
"v6.18.42",
"v6.18.41",
"v6.18.40",
"v6.6.161",
"v6.6.160",
"v7.1.13",
"v7.1.12",
"v7.1.11",
"v7.1.10",
"v7.1.9",
"v7.1.8",
"v7.1.7",
"v7.1.6",
"v7.1.5"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90220.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.12.110"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.13.0"
},
{
"fixed": "6.18.52"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.19.0"
},
{
"fixed": "7.2.6"
}
]
}
],
"package": {
"name": "Kernel",
"ecosystem": "Linux"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90220.json"
}
}
],
"modified": "2026-11-01T02:30:31.952805831Z",
"provider": "osv",
"references": [
"https://git.kernel.org/stable/c/42c3f856d13a91a0d4c302a0c6854813621136db",
"https://git.kernel.org/stable/c/59e1592d3c270ff4642d5d6dc55c545306eb0693",
"https://git.kernel.org/stable/c/6e6e471eef1d5d8cb056c7d364023fe048249204",
"https://git.kernel.org/stable/c/b1e8d40663997aacaa198f37ce6893e07aaba77a",
"https://git.kernel.org/stable/c/c92b2e6e418a3885758438dddcead6e954a9e095",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90220.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-90220",
"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
],
"provider_metadata": {
"cna_assigner": "Linux",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90220.json"
}
},
"related_cves": [
{
"value": "CVE-2026-90220",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 518147,
"published_at": "2026-09-17T16:07:31.423+00:00"
}