CVE-2026-63923 (GCVE-0-2026-63923)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:55 – Updated: 2026-07-20 13:41
VLAI
Title
octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify
Summary
In the Linux kernel, the following vulnerability has been resolved: octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify rvu_mbox_handler_rep_event_notify() in drivers/net/ethernet/marvell/ octeontx2/af/rvu_rep.c queues a sender-controlled REP_EVENT_NOTIFY request body verbatim, and rvu_rep_up_notify() then forwards event->pcifunc (the nested body field, distinct from the AF-normalised header pcifunc) into rvu_get_pfvf(), rvu_get_pf() and the AF->PF mailbox device index without any bounds check. A VF attached to a PF that has been put into switchdev representor mode reaches this path: the VF mailbox handler otx2_pfvf_mbox_handler() forwards every message id including MBOX_MSG_REP_EVENT_NOTIFY to AF without an allowlist, and the AF dispatcher rewrites only msg->pcifunc, leaving struct rep_event::pcifunc attacker-controlled. The sibling rvu_mbox_handler_esw_cfg() refuses requests whose header pcifunc is not rvu->rep_pcifunc; this handler has no equivalent gate. An out-of-range body pcifunc selects an &rvu->pf[]/&rvu->hwvf[] element past the allocated array and, for RVU_EVENT_MAC_ADDR_CHANGE, turns into a six-byte attacker-chosen OOB ether_addr_copy() target inside the queued worker; KASAN reports a slab-out-of-bounds write in rvu_rep_wq_handler. Reject malformed requests at the handler entry by gating on is_pf_func_valid(), which is already the canonical PF/VF range check in this driver; expose it via rvu.h so callers in rvu_rep.c can use it instead of open-coding the same range arithmetic.
Severity
8.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: b8fea84a0468404fe3b3327ad54d583950be9dec , < 68be0260e2a02ff9b18a8678d5f8d1715fa20138 (git)
Affected: b8fea84a0468404fe3b3327ad54d583950be9dec , < 2156a29aecfffa2eb7c558255690084efbe9f3b0 (git)
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Linux Linux Affected: 6.13
Unaffected: 0 , < 6.13 (semver)
Unaffected: 7.0.12 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/marvell/octeontx2/af/rvu.c",
            "drivers/net/ethernet/marvell/octeontx2/af/rvu.h",
            "drivers/net/ethernet/marvell/octeontx2/af/rvu_rep.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "68be0260e2a02ff9b18a8678d5f8d1715fa20138",
              "status": "affected",
              "version": "b8fea84a0468404fe3b3327ad54d583950be9dec",
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              "versionType": "git"
            }
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          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/marvell/octeontx2/af/rvu.c",
            "drivers/net/ethernet/marvell/octeontx2/af/rvu.h",
            "drivers/net/ethernet/marvell/octeontx2/af/rvu_rep.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "6.13"
            },
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              "status": "unaffected",
              "version": "0",
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              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
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                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
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                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocteontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify\n\nrvu_mbox_handler_rep_event_notify() in drivers/net/ethernet/marvell/\nocteontx2/af/rvu_rep.c queues a sender-controlled REP_EVENT_NOTIFY\nrequest body verbatim, and rvu_rep_up_notify() then forwards\nevent-\u003epcifunc (the nested body field, distinct from the\nAF-normalised header pcifunc) into rvu_get_pfvf(), rvu_get_pf() and\nthe AF-\u003ePF mailbox device index without any bounds check.\n\nA VF attached to a PF that has been put into switchdev\nrepresentor mode reaches this path: the VF mailbox handler\notx2_pfvf_mbox_handler() forwards every message id including\nMBOX_MSG_REP_EVENT_NOTIFY to AF without an allowlist, and the AF\ndispatcher rewrites only msg-\u003epcifunc, leaving struct\nrep_event::pcifunc attacker-controlled.  The sibling\nrvu_mbox_handler_esw_cfg() refuses requests whose header pcifunc\nis not rvu-\u003erep_pcifunc; this handler has no equivalent gate.\n\nAn out-of-range body pcifunc selects an \u0026rvu-\u003epf[]/\u0026rvu-\u003ehwvf[]\nelement past the allocated array and, for RVU_EVENT_MAC_ADDR_CHANGE,\nturns into a six-byte attacker-chosen OOB ether_addr_copy() target\ninside the queued worker; KASAN reports a slab-out-of-bounds write\nin rvu_rep_wq_handler.\n\nReject malformed requests at the handler entry by gating on\nis_pf_func_valid(), which is already the canonical PF/VF range check\nin this driver; expose it via rvu.h so callers in rvu_rep.c can use\nit instead of open-coding the same range arithmetic."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T13:41:33.104Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/68be0260e2a02ff9b18a8678d5f8d1715fa20138"
        },
        {
          "url": "https://git.kernel.org/stable/c/2156a29aecfffa2eb7c558255690084efbe9f3b0"
        }
      ],
      "title": "octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63923",
    "datePublished": "2026-07-19T14:55:24.985Z",
    "dateReserved": "2026-07-19T07:54:57.021Z",
    "dateUpdated": "2026-07-20T13:41:33.104Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-63923",
      "date": "2026-07-21",
      "epss": "0.00154",
      "percentile": "0.04984"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-63923\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-19T16:17:10.560\",\"lastModified\":\"2026-07-20T15:16:56.730\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nocteontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify\\n\\nrvu_mbox_handler_rep_event_notify() in drivers/net/ethernet/marvell/\\nocteontx2/af/rvu_rep.c queues a sender-controlled REP_EVENT_NOTIFY\\nrequest body verbatim, and rvu_rep_up_notify() then forwards\\nevent-\u003epcifunc (the nested body field, distinct from the\\nAF-normalised header pcifunc) into rvu_get_pfvf(), rvu_get_pf() and\\nthe AF-\u003ePF mailbox device index without any bounds check.\\n\\nA VF attached to a PF that has been put into switchdev\\nrepresentor mode reaches this path: the VF mailbox handler\\notx2_pfvf_mbox_handler() forwards every message id including\\nMBOX_MSG_REP_EVENT_NOTIFY to AF without an allowlist, and the AF\\ndispatcher rewrites only msg-\u003epcifunc, leaving struct\\nrep_event::pcifunc attacker-controlled.  The sibling\\nrvu_mbox_handler_esw_cfg() refuses requests whose header pcifunc\\nis not rvu-\u003erep_pcifunc; this handler has no equivalent gate.\\n\\nAn out-of-range body pcifunc selects an \u0026rvu-\u003epf[]/\u0026rvu-\u003ehwvf[]\\nelement past the allocated array and, for RVU_EVENT_MAC_ADDR_CHANGE,\\nturns into a six-byte attacker-chosen OOB ether_addr_copy() target\\ninside the queued worker; KASAN reports a slab-out-of-bounds write\\nin rvu_rep_wq_handler.\\n\\nReject malformed requests at the handler entry by gating on\\nis_pf_func_valid(), which is already the canonical PF/VF range check\\nin this driver; expose it via rvu.h so callers in rvu_rep.c can use\\nit instead of open-coding the same range arithmetic.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/net/ethernet/marvell/octeontx2/af/rvu.c\",\"drivers/net/ethernet/marvell/octeontx2/af/rvu.h\",\"drivers/net/ethernet/marvell/octeontx2/af/rvu_rep.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"b8fea84a0468404fe3b3327ad54d583950be9dec\",\"lessThan\":\"68be0260e2a02ff9b18a8678d5f8d1715fa20138\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"b8fea84a0468404fe3b3327ad54d583950be9dec\",\"lessThan\":\"2156a29aecfffa2eb7c558255690084efbe9f3b0\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/net/ethernet/marvell/octeontx2/af/rvu.c\",\"drivers/net/ethernet/marvell/octeontx2/af/rvu.h\",\"drivers/net/ethernet/marvell/octeontx2/af/rvu_rep.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.13\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.13\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.12\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"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:C/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.0,\"impactScore\":6.0}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2156a29aecfffa2eb7c558255690084efbe9f3b0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/68be0260e2a02ff9b18a8678d5f8d1715fa20138\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-07-21T21:30:45+00:00",
      "cve": "CVE-2026-63923",
      "id": "CVE-2026-63923",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63923.json",
      "version": "3"
    }
  }
}



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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

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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.