CVE-2026-74629 (GCVE-0-2026-74629)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:32 – Updated: 2026-08-25 05:40
VLAI
Title
net/dibs: Correct freeing of dmb_clientid_arr
Summary
In the Linux kernel, the following vulnerability has been resolved: net/dibs: Correct freeing of dmb_clientid_arr A dibs device interrupt handler can be active after dibs_dev_del() and may still access dmb_clientid_arr. (UAF) In case of a failure in dibs_dev_add() being called by dibs_lo_dev_probe() dmb_clientid_arr is freed twice (double free). Free dmb_clientid_arr in dibs_dev_release() after last reference is gone. Note that allocating in dibs_dev_add() instead of dibs_dev_alloc() is ok for now, because no dmbs can be registered before dibs_dev_add().
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: cc21191b584c6f7836b0f10774f8278b7cbfba10 , < ece6426b61241e9bfb41aa131f235168f55229b1 (git)
Affected: cc21191b584c6f7836b0f10774f8278b7cbfba10 , < 7a1df20a8d2cc89e3a442b6e0b43b1cacde8d403 (git)
Affected: cc21191b584c6f7836b0f10774f8278b7cbfba10 , < 9e6869be49064915edb6c8776b27c376cfdb0df5 (git)
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Linux Linux Affected: 6.18
Unaffected: 0 , < 6.18 (semver)
Unaffected: 6.18.45 , ≤ 6.18.* (semver)
Unaffected: 7.1.9 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/dibs/dibs_loopback.c",
            "drivers/dibs/dibs_main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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          "vendor": "Linux",
          "versions": [
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              "version": "6.18"
            },
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              "version": "7.1.9",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
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        }
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      "cpeApplicability": [
        {
          "nodes": [
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              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "6.18",
                  "vulnerable": true
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                  "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\nnet/dibs: Correct freeing of dmb_clientid_arr\n\nA dibs device interrupt handler can be active after dibs_dev_del() and\nmay still access dmb_clientid_arr. (UAF)\n\nIn case of a failure in dibs_dev_add() being called by dibs_lo_dev_probe()\ndmb_clientid_arr is freed twice (double free).\n\nFree dmb_clientid_arr in dibs_dev_release() after last reference is gone.\nNote that allocating in dibs_dev_add() instead of dibs_dev_alloc() is ok\nfor now, because no dmbs can be registered before dibs_dev_add()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:A - The UAF is hit when an ISM interrupt handler reads dmb_clientid_arr during SMC-D data transfer from a co-located peer on the same IBM Z CPC/HiperSockets domain; this is an adjacent-network attack surface, not arbitrary Internet reachability.\nAC:L - An attacker controls the IRQ side by sustaining SMC-D transfers that keep firing ism_handle_irq while device teardown runs; no rare memory layout or victim-specific state beyond concurrent traffic during hot-unplug/module removal is required.\nPR:N - Exploitation requires only an established SMC-D peer sending data to the victim; no Linux capabilities, root, or user-namespace privileges on the victim host are needed to drive the interrupt path that accesses the freed array.\nUI:N - No victim user action is required; the bug is triggered by remote SMC-D traffic coinciding with kernel driver teardown, not by opening files, mounting filesystems, or other interactive steps.\nS:U - Successful exploitation corrupts kernel heap memory and enables privilege escalation within the same kernel security domain; it does not by itself cross a VM/hypervisor or IOMMU boundary to another authority.\nC:H - The use-after-free of dmb_clientid_arr in ism_handle_irq permits out-of-bounds or attacker-influenced kernel heap reads that can disclose sensitive memory, including pointers usable in further exploitation.\nI:H - UAF on a heap-allocated client-ID lookup table in IRQ context can be turned into arbitrary kernel memory writes and control-flow hijacking via heap grooming and reuse of the freed allocation.\nA:H - Concurrent access to freed dmb_clientid_arr during interrupt handling can cause kernel oops/panic or wedged SMC-D processing, producing complete loss of availability on affected IBM Z systems."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T05:40:53.253Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ece6426b61241e9bfb41aa131f235168f55229b1"
        },
        {
          "url": "https://git.kernel.org/stable/c/7a1df20a8d2cc89e3a442b6e0b43b1cacde8d403"
        },
        {
          "url": "https://git.kernel.org/stable/c/9e6869be49064915edb6c8776b27c376cfdb0df5"
        }
      ],
      "title": "net/dibs: Correct freeing of dmb_clientid_arr",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74629",
    "datePublished": "2026-08-22T15:32:10.861Z",
    "dateReserved": "2026-08-15T05:44:03.921Z",
    "dateUpdated": "2026-08-25T05:40:53.253Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-09-01",
      "epss": "0.00239",
      "percentile": "0.14794"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-74629\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-22T16:16:35.840\",\"lastModified\":\"2026-08-25T06:18:41.710\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnet/dibs: Correct freeing of dmb_clientid_arr\\n\\nA dibs device interrupt handler can be active after dibs_dev_del() and\\nmay still access dmb_clientid_arr. (UAF)\\n\\nIn case of a failure in dibs_dev_add() being called by dibs_lo_dev_probe()\\ndmb_clientid_arr is freed twice (double free).\\n\\nFree dmb_clientid_arr in dibs_dev_release() after last reference is gone.\\nNote that allocating in dibs_dev_add() instead of dibs_dev_alloc() is ok\\nfor now, because no dmbs can be registered before dibs_dev_add().\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/dibs/dibs_loopback.c\",\"drivers/dibs/dibs_main.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"cc21191b584c6f7836b0f10774f8278b7cbfba10\",\"lessThan\":\"ece6426b61241e9bfb41aa131f235168f55229b1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cc21191b584c6f7836b0f10774f8278b7cbfba10\",\"lessThan\":\"7a1df20a8d2cc89e3a442b6e0b43b1cacde8d403\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cc21191b584c6f7836b0f10774f8278b7cbfba10\",\"lessThan\":\"9e6869be49064915edb6c8776b27c376cfdb0df5\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/dibs/dibs_loopback.c\",\"drivers/dibs/dibs_main.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.18\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.18\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.45\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.9\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"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:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/7a1df20a8d2cc89e3a442b6e0b43b1cacde8d403\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9e6869be49064915edb6c8776b27c376cfdb0df5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ece6426b61241e9bfb41aa131f235168f55229b1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-25T08:51:42+00:00",
      "cve": "CVE-2026-74629",
      "id": "CVE-2026-74629",
      "initial_release_date": "2026-08-22T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net/dibs: Correct freeing of dmb_clientid_arr",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74629.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.