CVE-2026-89547 (GCVE-0-2026-89547)
Vulnerability from cvelistv5 – Published: 2026-09-11 19:44 – Updated: 2026-10-19 08:48
VLAI
EPSS
VEX
Title
SUNRPC: Check svc pool percpu counter allocation
Summary
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Check svc pool percpu counter allocation
__svc_create() initializes three per-pool percpu_counter stats and
ignores every return value. On SMP, percpu_counter_init() fails when
__alloc_percpu_gfp() cannot satisfy the allocation, leaving the failed
counter with fbc->counters == NULL and its embedded raw_spinlock_t,
list_head, and count never initialized. __svc_create() returns the
half-constructed svc_serv to nfsd, lockd, or the NFS callback service
anyway.
Once that service is live, the hot-path increments in
svc_xprt_enqueue(), svc_handle_xprt(), and
svc_pool_wake_idle_thread() reach a counter whose backing pointer is
NULL. The pointer is a per-cpu offset, so the access does not fault:
it resolves to offset zero of the current CPU's per-cpu area and
silently corrupts whatever variable lives there. A
/proc/fs/nfsd/pool_stats read walks the same NULL per-cpu storage and
returns garbage, and on CONFIG_DEBUG_SPINLOCK or lockdep it splats on
the never-initialized lock.
Creating the broken service requires a percpu allocation failure during
RPC server startup, so it is reachable only by a local administrator
under memory pressure or fault injection; a remote peer cannot induce
the bad state on its own.
Check each percpu_counter_init() return value in __svc_create() and
fail when an allocation fails, unwinding the counters already set up
in the current pool and in every pool initialized before it. A
discrete percpu_counter_destroy() per counter at teardown frees each
per-cpu allocation exactly once.
Severity
8.1 (High)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < 57ac7d899409b0a9b768cf417e3bb86bcca3d4c6
(git)
Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < 3a2b7649de76376a69f1d3ed2a539fb15907cd4d (git) Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < bd1ef2cfb44d72b7aa6943e87b206eb0e30fbd0c (git) Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < b541a15046976e481618726cc23db0fb22d576db (git) Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < 43e11e164704dde975c9edb370de1a06bec67270 (git) |
guessed | |
| Linux | Linux |
Affected:
6.3
Unaffected: 0 , < 6.3 (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.109 , ≤ 6.12.* (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/sunrpc/svc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "57ac7d899409b0a9b768cf417e3bb86bcca3d4c6",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "3a2b7649de76376a69f1d3ed2a539fb15907cd4d",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "bd1ef2cfb44d72b7aa6943e87b206eb0e30fbd0c",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "b541a15046976e481618726cc23db0fb22d576db",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "43e11e164704dde975c9edb370de1a06bec67270",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/sunrpc/svc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.3"
},
{
"lessThan": "6.3",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.157",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.109",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.50",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.4",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "6.3",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: Check svc pool percpu counter allocation\n\n__svc_create() initializes three per-pool percpu_counter stats and\nignores every return value. On SMP, percpu_counter_init() fails when\n__alloc_percpu_gfp() cannot satisfy the allocation, leaving the failed\ncounter with fbc-\u003ecounters == NULL and its embedded raw_spinlock_t,\nlist_head, and count never initialized. __svc_create() returns the\nhalf-constructed svc_serv to nfsd, lockd, or the NFS callback service\nanyway.\n\nOnce that service is live, the hot-path increments in\nsvc_xprt_enqueue(), svc_handle_xprt(), and\nsvc_pool_wake_idle_thread() reach a counter whose backing pointer is\nNULL. The pointer is a per-cpu offset, so the access does not fault:\nit resolves to offset zero of the current CPU\u0027s per-cpu area and\nsilently corrupts whatever variable lives there. A\n/proc/fs/nfsd/pool_stats read walks the same NULL per-cpu storage and\nreturns garbage, and on CONFIG_DEBUG_SPINLOCK or lockdep it splats on\nthe never-initialized lock.\n\nCreating the broken service requires a percpu allocation failure during\nRPC server startup, so it is reachable only by a local administrator\nunder memory pressure or fault injection; a remote peer cannot induce\nthe bad state on its own.\n\nCheck each percpu_counter_init() return value in __svc_create() and\nfail when an allocation fails, unwinding the counters already set up\nin the current pool and in every pool initialized before it. A\ndiscrete percpu_counter_destroy() per counter at teardown frees each\nper-cpu allocation exactly once."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - After nfsd, lockd, or the NFS-callback SUNRPC service is created with a failed pool percpu_counter, svc_xprt_enqueue(), svc_handle_xprt(), and svc_pool_wake_idle_thread() increment those counters on the packet-receive hot path, so a remote NFS/NLM/callback peer triggers the corruption by sending RPC traffic (typically TCP/2049).\nAC:H - The broken service exists only if percpu_counter_init() fails inside __svc_create() during RPC server startup; that tiny per-CPU allocation failure requires memory pressure or fault injection that a remote peer cannot induce, so success depends on a startup condition the attacker cannot control.\nPR:N - svc_xprt_enqueue() and svc_handle_xprt() run when a SUNRPC transport has received data, before RPC authentication, so an unauthenticated network client needs no host account or capabilities to deliver the traffic that hits the NULL counters.\nUI:N - Exploitation is inbound RPC to an already-running nfsd, lockd, or NFS callback listener; no administrator or end-user action such as mounting a filesystem or opening a file is required at exploit time.\nS:U - Per-CPU corruption, pool_stats disclosure, and any resulting oops stay inside the host kernel\u0027s SUNRPC/nfsd authority and do not cross a VM, IOMMU, or other security boundary.\nC:H - A NULL fbc-\u003ecounters pointer is treated as a per-CPU offset, so increments and percpu_counter_sum_positive() read offset 0 of each CPU\u0027s per-CPU area; world-readable nfsd pool_stats returns those values, giving a kernel-memory disclosure primitive from the same corruption.\nI:H - percpu_counter_inc() cmpxchg-increments and the batch-fold path later zeroes the s32 at per-CPU offset 0 via __this_cpu_sub(), silently corrupting whatever kernel per-CPU variable lives there and yielding a write primitive against that storage rather than a contained stats-only update.\nA:H - The never-initialized counter lock/lockdep map can splat under CONFIG_DEBUG_SPINLOCK or lockdep, and corrupting the CPU\u0027s per-CPU area can oops or panic the host, so the bug is a kernel crash/DoS even when not fully exploited."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T08:48:38.898Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/57ac7d899409b0a9b768cf417e3bb86bcca3d4c6"
},
{
"url": "https://git.kernel.org/stable/c/3a2b7649de76376a69f1d3ed2a539fb15907cd4d"
},
{
"url": "https://git.kernel.org/stable/c/bd1ef2cfb44d72b7aa6943e87b206eb0e30fbd0c"
},
{
"url": "https://git.kernel.org/stable/c/b541a15046976e481618726cc23db0fb22d576db"
},
{
"url": "https://git.kernel.org/stable/c/43e11e164704dde975c9edb370de1a06bec67270"
}
],
"title": "SUNRPC: Check svc pool percpu counter allocation",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-89547",
"datePublished": "2026-09-11T19:44:22.644Z",
"dateReserved": "2026-09-11T19:38:34.722Z",
"dateUpdated": "2026-10-19T08:48:38.898Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-89547",
"date": "2026-11-09",
"epss": "0.00561",
"percentile": "0.46933"
},
"microsoft_vex": {
"current_release_date": "2026-09-23T14:51:32.000Z",
"cve": "CVE-2026-89547",
"id": "msrc_CVE-2026-89547",
"initial_release_date": "2026-09-13T01:03:00.000Z",
"product_status:fixed": "1",
"product_status:known_affected": "2",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "SUNRPC: Check svc pool percpu counter allocation",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89547.json",
"version": "4"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/sunrpc/svc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "57ac7d899409b0a9b768cf417e3bb86bcca3d4c6",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "3a2b7649de76376a69f1d3ed2a539fb15907cd4d",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "bd1ef2cfb44d72b7aa6943e87b206eb0e30fbd0c",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "b541a15046976e481618726cc23db0fb22d576db",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
},
{
"lessThan": "43e11e164704dde975c9edb370de1a06bec67270",
"status": "affected",
"version": "ccf08bed6e7a80519569456edd2ea21b7b1701c6",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/sunrpc/svc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.3"
},
{
"lessThan": "6.3",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: Check svc pool percpu counter allocation\n\n__svc_create() initializes three per-pool percpu_counter stats and\nignores every return value. On SMP, percpu_counter_init() fails when\n__alloc_percpu_gfp() cannot satisfy the allocation, leaving the failed\ncounter with fbc-\u003ecounters == NULL and its embedded raw_spinlock_t,\nlist_head, and count never initialized. __svc_create() returns the\nhalf-constructed svc_serv to nfsd, lockd, or the NFS callback service\nanyway.\n\nOnce that service is live, the hot-path increments in\nsvc_xprt_enqueue(), svc_handle_xprt(), and\nsvc_pool_wake_idle_thread() reach a counter whose backing pointer is\nNULL. The pointer is a per-cpu offset, so the access does not fault:\nit resolves to offset zero of the current CPU\u0027s per-cpu area and\nsilently corrupts whatever variable lives there. A\n/proc/fs/nfsd/pool_stats read walks the same NULL per-cpu storage and\nreturns garbage, and on CONFIG_DEBUG_SPINLOCK or lockdep it splats on\nthe never-initialized lock.\n\nCreating the broken service requires a percpu allocation failure during\nRPC server startup, so it is reachable only by a local administrator\nunder memory pressure or fault injection; a remote peer cannot induce\nthe bad state on its own.\n\nCheck each percpu_counter_init() return value in __svc_create() and\nfail when an allocation fails, unwinding the counters already set up\nin the current pool and in every pool initialized before it. A\ndiscrete percpu_counter_destroy() per counter at teardown frees each\nper-cpu allocation exactly once."
}
],
"id": "CVE-2026-89547",
"lastModified": "2026-10-19T09:17:49.830",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.1,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.2,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-09-11T20:19:38.107",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3a2b7649de76376a69f1d3ed2a539fb15907cd4d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/43e11e164704dde975c9edb370de1a06bec67270"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/57ac7d899409b0a9b768cf417e3bb86bcca3d4c6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b541a15046976e481618726cc23db0fb22d576db"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/bd1ef2cfb44d72b7aa6943e87b206eb0e30fbd0c"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-11-06T01:17:40+00:00",
"cve": "CVE-2026-89547",
"id": "CVE-2026-89547",
"initial_release_date": "2026-09-11T00:00:00+00:00",
"product_status:known_affected": "124",
"product_status:known_not_affected": "79",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: SUNRPC: Check svc pool percpu counter allocation",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89547.json",
"version": "3"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.