net/sched: fq_pie: clamp default quantum to avoid signed overflow
In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: clamp default quantum to avoid signed overflow fq_pie_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) without clamping. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes psched_mtu() return 0x80000000, which overflows the signed flow->deficit to INT_MIN in fq_pie_qdisc_dequeue(), causing an infinite loop and soft lockup. Emulate fq_pie_policy which is already bounded to [1, 1 << 20]; clamp the default to [256, 1 << 20]. 256 matches fq_codel's floor and is a sane minimum for a DRR quantum. Conditions to recreate the bug: a device whose MTU (plus hard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy device with max_mtu == 0 accepting MTU 2147483634). Requires CAP_NET_ADMIN in a user namespace.
CVE-2026-90074
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-90074
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "1f43e4dbc93b7d02761a024d5f895df823c07b72",
"versionType": "git"
},
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "f7942b2693bc24c7d609a03d06f97bee3b0bd96a",
"versionType": "git"
},
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "6f1be05faecef4c0f9a008200209f66ef2e133f7",
"versionType": "git"
},
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "435da3734a8e63d3067016accc977ed1d10aaaa0",
"versionType": "git"
},
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "44dad8fe99b58a7fe2961e9eec6a5f07ace5b51f",
"versionType": "git"
},
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "044fa2498bbc2900f0c48a6ef2fdd5b2bdfc3795",
"versionType": "git"
},
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "bf97fd2163ad1191ef8daa3d4df8372aee19e396",
"versionType": "git"
},
{
"status": "affected",
"version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
"lessThan": "c86cd7ed0b0e44779a3d1683f03e4353baf4bdc9",
"versionType": "git"
}
],
"programFiles": [
"net/sched/sch_fq_pie.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.6"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.6",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/sch_fq_pie.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90074
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36490 · Revision 1
- Added to Heist Feed
- Publisher date