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vuln-cve/data/2026/89xxx/CVE-2026-89709.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-89709",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"state": "PUBLISHED",
"assignerShortName": "Linux",
"dateReserved": "2026-09-11T19:38:34.751Z",
"datePublished": "2026-09-11T19:46:24.803Z",
"dateUpdated": "2026-10-30T12:32:47.602Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-10-30T12:32:47.602Z"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlockd, nfsd: RCU-protect nlmsvc_ops dispatch\n\nnlmsvc_ops is published by nfsd_lockd_init() and cleared by\nnfsd_lockd_shutdown() with plain stores, while lockd dereferences\nit unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer\ntargets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's\n.text, so a stale load after rmmod nfsd results in either a NULL\nderef or a module-text use-after-free.\n\nDeclare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear\nvia RCU_INIT_POINTER() + synchronize_rcu(). Add a struct module\n*owner field to nlmsvc_binding and pin the module across indirect\ncalls with try_module_get/module_put. When the binding is torn down,\nfall back to fput() to avoid leaking struct file references."
}
],
"metrics": [
{
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 8.1,
"baseSeverity": "HIGH"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - lockd is the in-kernel NLM RPC server on TCP/UDP (rpcbind-registered) used with nfsd. nlm_do_fopen() and nlm_delete_file() run from NLM LOCK/TEST/UNLOCK/FREE_ALL in svc_recv, so a remote NFS/NLM peer reaches the unguarded nlmsvc_ops->fopen/fclose dispatch.\nAC:H - The UAF requires exit_nfsd()/rmmod nfsd to NULL nlmsvc_ops with a plain store and free nfsd .text while lockd still dispatches. A remote attacker can flood NLM requests but cannot unload nfsd; that victim-side module teardown is beyond attacker control.\nPR:N - lockd_authenticate() accepts RPC_AUTH_NULL and RPC_AUTH_UNIX before procedure dispatch. nlm_fopen() uses NFSD_MAY_BYPASS_GSS|NFSD_MAY_NLM, and typical exports use AUTH_SYS, so no host account or capability is required.\nUI:N - Exploitation is driven by attacker-sent NLM RPCs to an already-running lockd; no victim user must mount a filesystem or open a file. nfsd unload is an environmental timing condition, not User Interaction.\nS:U - The module-text UAF and NULL deref corrupt host kernel lockd/nfsd state within the same OS security authority and do not cross a VM, IOMMU, or sandbox boundary.\nC:H - After rmmod, a stale nlmsvc_ops load calls fopen/fclose from freed nfsd .rodata/.text. Reclaim of those module pages lets the attacker control the indirect-call target, yielding an arbitrary kernel read per UAF guidance.\nI:H - Indirect call through a dangling nlmsvc_binding in freed nfsd module memory is a RIP-hijack primitive; spraying recycled module pages enables arbitrary kernel write and control-flow hijack, so integrity impact is high.\nA:H - A stale nlmsvc_ops load after rmmod nfsd is either a NULL deref or a call into unmapped module text; both oops/panic the kernel, so availability impact is high."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/lockd/svc.c",
"fs/lockd/svc4proc.c",
"fs/lockd/svcproc.c",
"fs/lockd/svcsubs.c",
"fs/nfsd/lockd.c",
"include/linux/lockd/bind.h"
],
"versions": [
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "cc2f0d79b21be69b891cbd1899daf2a1fdf9df87",
"status": "affected",
"versionType": "git"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "43943532c105ea8fe26039a1347cfda4ac0fcadc",
"status": "affected",
"versionType": "git"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "6e7495972039f212e336e552b58cac9dd54611c3",
"status": "affected",
"versionType": "git"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "836ce2b99bcce6d68c58edd04efbc5cd1fd581af",
"status": "affected",
"versionType": "git"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "3c461a1820088fb5889d73a6522369bde45527a9",
"status": "affected",
"versionType": "git"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "641e5e20852359b8c31149be4598884e30652f60",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/lockd/svc.c",
"fs/lockd/svc4proc.c",
"fs/lockd/svcproc.c",
"fs/lockd/svcsubs.c",
"fs/nfsd/lockd.c",
"include/linux/lockd/bind.h"
],
"versions": [
{
"version": "2.6.12",
"status": "affected"
},
{
"version": "0",
"lessThan": "2.6.12",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.12.114",
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.18.57",
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.2.4",
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.6.12",
"versionEndExcluding": "6.1.191"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.6.12",
"versionEndExcluding": "6.6.160"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.6.12",
"versionEndExcluding": "6.12.114"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.6.12",
"versionEndExcluding": "6.18.57"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.6.12",
"versionEndExcluding": "7.2.4"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.6.12",
"versionEndExcluding": "7.3"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/cc2f0d79b21be69b891cbd1899daf2a1fdf9df87"
},
{
"url": "https://git.kernel.org/stable/c/43943532c105ea8fe26039a1347cfda4ac0fcadc"
},
{
"url": "https://git.kernel.org/stable/c/6e7495972039f212e336e552b58cac9dd54611c3"
},
{
"url": "https://git.kernel.org/stable/c/836ce2b99bcce6d68c58edd04efbc5cd1fd581af"
},
{
"url": "https://git.kernel.org/stable/c/3c461a1820088fb5889d73a6522369bde45527a9"
},
{
"url": "https://git.kernel.org/stable/c/641e5e20852359b8c31149be4598884e30652f60"
}
],
"title": "lockd, nfsd: RCU-protect nlmsvc_ops dispatch",
"x_generator": {
"engine": "bippy-1.2.0"
}
},
"adp": [
{
"metrics": [
{
"other": {
"type": "ssvc",
"content": {
"id": "CVE-2026-89709",
"role": "CISA Coordinator",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-10-16T19:26:23.054440Z"
}
}
}
],
"title": "CISA ADP Vulnrichment",
"providerMetadata": {
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP",
"dateUpdated": "2026-10-16T19:36:59.347Z"
}
}
]
}
}