CVE-2026-89684
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix cpntf publish race in nfs4_init_cp_state nfs4_alloc_init_cpntf_state() published the new cpntf entry into the s2s_cp_stateids IDR (with cs_type set) in one s2s_cp_lock section, then took the lock again to list_add() it onto p_stid->sc_cp_list. In the gap the entry is reachable by so_id but cp_list is still {NULL,NULL} from kzalloc. A racing OFFLOAD_CANCEL (so_id is echoed to the client as cnr_stateid, so any NFSv4.2 client can drive it) reaches manage_cpntf_state() -> _free_cpntf_state_locked() and does list_del() on the zeroed list_head, oopsing the server. Fold the cs_type assignment and the list_add() into the same critical section as idr_alloc_cyclic(), so a concurrent lookup either misses the entry or sees a fully linked cp_list. INIT_LIST_HEAD() the entry after allocation and switch _free_cpntf_state_locked() to list_del_init() so a stale unlink is a no-op. nfs4_init_copy_state() passes NULL p_stid and skips the list_add, preserving NFS4_COPY_STID semantics.
Severity
HIGH
CVSS score
7.5
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-11 20:19:55.300000
Last modified
2026-10-19 09:18:06.760000
View original CVE JSON
{
"id": "CVE-2026-89684",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-11T20:19:55.300",
"lastModified": "2026-10-19T09:18:06.760",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix cpntf publish race in nfs4_init_cp_state\n\nnfs4_alloc_init_cpntf_state() published the new cpntf entry into the\ns2s_cp_stateids IDR (with cs_type set) in one s2s_cp_lock section, then\ntook the lock again to list_add() it onto p_stid->sc_cp_list. In the gap\nthe entry is reachable by so_id but cp_list is still {NULL,NULL} from\nkzalloc. A racing OFFLOAD_CANCEL (so_id is echoed to the client as\ncnr_stateid, so any NFSv4.2 client can drive it) reaches\nmanage_cpntf_state() -> _free_cpntf_state_locked() and does list_del() on\nthe zeroed list_head, oopsing the server.\n\nFold the cs_type assignment and the list_add() into the same critical\nsection as idr_alloc_cyclic(), so a concurrent lookup either misses the\nentry or sees a fully linked cp_list. INIT_LIST_HEAD() the entry after\nallocation and switch _free_cpntf_state_locked() to list_del_init() so a\nstale unlink is a no-op. nfs4_init_copy_state() passes NULL p_stid and\nskips the list_add, preserving NFS4_COPY_STID semantics."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/nfsd/nfs4state.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "624322f1adc58acd0b69f77a6ddc764207e97241",
"lessThan": "63e18fc65587fd3f7b4c6d70e96d32fc41d82ba3",
"versionType": "git",
"status": "affected"
},
{
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"status": "affected"
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},
{
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"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/nfsd/nfs4state.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.6",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.6",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.270",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.221",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.188",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.157",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.109",
"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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/21d6c5957f5ca97d7352e60f55ea412beb9419f5",
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{
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{
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}