linux — security advisory
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_fq: fix integer overflow of "credit" if sch_fq is configured with "initial quantum" having values greater than INT_MAX, the first assignment of "credit" does signed integer overflow to a very negative value. In this situation, the syzkaller script provided by Cristoph triggers the CPU soft-lockup warning even with few sockets. It's not an infinite loop, but "credit" wasn't probably meant to be minus 2Gb for each new flow. Capping "initial quantum" to INT_MAX proved to fix the issue. v2: validation of "initial quantum" is done in fq_policy, instead of open coding in fq_change() _ suggested by Jakub Kicinski
- Products
- linux
- Affected versions
- 6.1.27-1
- Fixed versions
- 6.1.37-1, 6.3.7-1
- CVEs
- CVE-2023-53624
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 16:09 UTC · Revision 1
Source evidence
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_fq: fix integer overflow of "credit" if sch_fq is configured with "initial quantum" having values greater than INT_MAX, the first assignment of "credit" does signed integer overflow to a very negative value. In this situation, the syzkaller script provided by Cristoph triggers the CPU soft-lockup warning even with few sockets. It's not an infinite loop, but "credit" wasn't probably meant to be minus 2Gb for each new flow. Capping "initial quantum" to INT_MAX proved to fix the issue. v2: validation of "initial quantum" is done in fq_policy, instead of open coding in fq_change() _ suggested by Jakub Kicinski
osv:DEBIAN-CVE-2023-53624
linux
Fixed versions: 6.1.37-1
linux
Fixed versions: 6.3.7-1
linux
Fixed versions: 6.3.7-1
Complete source record
{
"id": "1c94b356f25b9f7e92e0790031b6ec950db92bb743417861d1a1212fdcee16f7",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2023-53624",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2023-53624",
"summary": "In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_fq: fix integer overflow of \"credit\" if sch_fq is configured with \"initial quantum\" having values greater than INT_MAX, the first assignment of \"credit\" does signed integer overflow to a very negative value. In this situation, the syzkaller script provided by Cristoph triggers the CPU soft-lockup warning even with few sockets. It's not an infinite loop, but \"credit\" wasn't probably meant to be minus 2Gb for each new flow. Capping \"initial quantum\" to INT_MAX proved to fix the issue. v2: validation of \"initial quantum\" is done in fq_policy, instead of open coding in fq_change() _ suggested by Jakub Kicinski",
"evidence": "osv:DEBIAN-CVE-2023-53624",
"products": [
{
"name": {
"value": "linux",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.1.37-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "6.1.27-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "linux",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.3.7-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "linux",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.3.7-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2023-53624",
"aliases": [
"DEBIAN-CVE-2023-53624"
],
"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": "6.1.37-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"6.1.27-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53624.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.3.7-1"
}
]
}
],
"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-2023-53624.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.3.7-1"
}
]
}
],
"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-2023-53624.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T18:02:45.500787278Z",
"provider": "osv",
"upstream": [
"CVE-2023-53624"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2023-53624"
]
},
"related_cves": [
{
"value": "CVE-2023-53624",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 456804,
"published_at": "2025-10-07T16:15:45.19+00:00"
}