linux — security advisory
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Limit the period size to 16MB Set the practical limit to the period size (the fragment shift in OSS) instead of a full 31bit; a too large value could lead to the exhaust of memory as we allocate temporary buffers of the period size, too. As of this patch, we set to 16MB limit, which should cover all use cases.
- Products
- linux
- Affected versions
- Not specified
- Fixed versions
- 5.15.15-1
- CVEs
- CVE-2021-47509
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 01:44 UTC · Revision 1
Source evidence
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Limit the period size to 16MB Set the practical limit to the period size (the fragment shift in OSS) instead of a full 31bit; a too large value could lead to the exhaust of memory as we allocate temporary buffers of the period size, too. As of this patch, we set to 16MB limit, which should cover all use cases.
osv:DEBIAN-CVE-2021-47509
linux
Fixed versions: 5.15.15-1
linux
Fixed versions: 5.15.15-1
linux
Fixed versions: 5.15.15-1
Complete source record
{
"id": "b3f53e07c98c190b803114a936018b1708028e2a72482e139ca160f3a7a24119",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-47509",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-47509",
"summary": "In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Limit the period size to 16MB Set the practical limit to the period size (the fragment shift in OSS) instead of a full 31bit; a too large value could lead to the exhaust of memory as we allocate temporary buffers of the period size, too. As of this patch, we set to 16MB limit, which should cover all use cases.",
"evidence": "osv:DEBIAN-CVE-2021-47509",
"products": [
{
"name": {
"value": "linux",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.15.15-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "linux",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.15.15-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "linux",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.15.15-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2021-47509",
"aliases": [
"DEBIAN-CVE-2021-47509"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.15.15-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47509.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.15.15-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47509.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.15.15-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47509.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:04:51.713346181Z",
"provider": "osv",
"upstream": [
"CVE-2021-47509"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-47509"
]
},
"related_cves": [
{
"value": "CVE-2021-47509",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 424171,
"published_at": "2024-05-24T15:15:11.78+00:00"
}