CVE-2026-89545
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: sunrpc: defer rq_argp and rq_resp free until after RCU grace period svc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously via kfree(), but defers the rqstp struct free via kfree_rcu(). After svc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is a window where RCU readers that started before list_del_rcu() can still traverse the thread list and find the rqstp. These readers (e.g. nfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has already been freed — a use-after-free. Fix this by moving the kfree of rq_argp and rq_resp into an explicit call_rcu() callback alongside the struct free. Resources not accessed by RCU readers (bvec, buffer pages, scratch folio, auth_data) remain synchronously freed.
Severity
HIGH
CVSS score
7.8
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-11 20:19:37.840000
Last modified
2026-10-30 13:20:21.040000
View original CVE JSON
{
"id": "CVE-2026-89545",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-11T20:19:37.840",
"lastModified": "2026-10-30T13:20:21.040",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: defer rq_argp and rq_resp free until after RCU grace period\n\nsvc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously\nvia kfree(), but defers the rqstp struct free via kfree_rcu(). After\nsvc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is\na window where RCU readers that started before list_del_rcu() can still\ntraverse the thread list and find the rqstp. These readers (e.g.\nnfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has\nalready been freed — a use-after-free.\n\nFix this by moving the kfree of rq_argp and rq_resp into an explicit\ncall_rcu() callback alongside the struct free. Resources not accessed\nby RCU readers (bvec, buffer pages, scratch folio, auth_data) remain\nsynchronously freed."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/sunrpc/svc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "812443865c5fc255363d4a684a62c086af1addca",
"lessThan": "c977158237bccc3d2512d5b17c47ee3760dc8839",
"versionType": "git",
"status": "affected"
},
{
"version": "812443865c5fc255363d4a684a62c086af1addca",
"lessThan": "0ea49d69aa806008b2424c8cf21cf746b9963967",
"versionType": "git",
"status": "affected"
},
{
"version": "812443865c5fc255363d4a684a62c086af1addca",
"lessThan": "08bc49e0541260bf294962cf889a32a2d2713ad6",
"versionType": "git",
"status": "affected"
},
{
"version": "812443865c5fc255363d4a684a62c086af1addca",
"lessThan": "e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090",
"versionType": "git",
"status": "affected"
},
{
"version": "812443865c5fc255363d4a684a62c086af1addca",
"lessThan": "c479bde671cbe2f9e152834a8b0eb7c3c295bbaf",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/sunrpc/svc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3.19",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.19",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.111",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.50",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.4",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T19:23:36.292382Z",
"id": "CVE-2026-89545",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/08bc49e0541260bf294962cf889a32a2d2713ad6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/0ea49d69aa806008b2424c8cf21cf746b9963967",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c479bde671cbe2f9e152834a8b0eb7c3c295bbaf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c977158237bccc3d2512d5b17c47ee3760dc8839",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}