Vulnerability-Lookup

FKIE_CVE-2026-89547

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-14 13:19

Severity

8.1 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3a2b7649de76376a69f1d3ed2a539fb15907cd4d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/43e11e164704dde975c9edb370de1a06bec67270
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/57ac7d899409b0a9b768cf417e3bb86bcca3d4c6
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b541a15046976e481618726cc23db0fb22d576db
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/bd1ef2cfb44d72b7aa6943e87b206eb0e30fbd0c

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "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-rc1",
              "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": "2026-09-14T13:19:09.543",
  "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"
}

CVE-2026-89547 (GCVE-0-2026-89547)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:44 – Updated: 2026-09-14 12:00

Title

SUNRPC: Check svc pool percpu counter allocation

Summary

Severity

8.1 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/57ac7d899409b0a9b…
https://git.kernel.org/stable/c/3a2b7649de76376a6…
https://git.kernel.org/stable/c/bd1ef2cfb44d72b7a…
https://git.kernel.org/stable/c/b541a15046976e481…
https://git.kernel.org/stable/c/43e11e164704dde97…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < 57ac7d899409b0a9b768cf417e3bb86bcca3d4c6 (git) Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < 3a2b7649de76376a69f1d3ed2a539fb15907cd4d (git) Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < bd1ef2cfb44d72b7aa6943e87b206eb0e30fbd0c (git) Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < b541a15046976e481618726cc23db0fb22d576db (git) Affected: ccf08bed6e7a80519569456edd2ea21b7b1701c6 , < 43e11e164704dde975c9edb370de1a06bec67270 (git)
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-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "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-rc1",
              "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-rc1",
                  "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": "2026-09-14T12:00:50.421Z",
        "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": "2026-09-14T12:00:50.421Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

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.

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.