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CVE-2026-23057 (GCVE-0-2026-23057)

Vulnerability from cvelistv5 – Published: 2026-02-04 16:07 – Updated: 2026-05-11 21:59
VLAI
Title
vsock/virtio: Coalesce only linear skb
Summary
In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: Coalesce only linear skb vsock/virtio common tries to coalesce buffers in rx queue: if a linear skb (with a spare tail room) is followed by a small skb (length limited by GOOD_COPY_LEN = 128), an attempt is made to join them. Since the introduction of MSG_ZEROCOPY support, assumption that a small skb will always be linear is incorrect. In the zerocopy case, data is lost and the linear skb is appended with uninitialized kernel memory. Of all 3 supported virtio-based transports, only loopback-transport is affected. G2H virtio-transport rx queue operates on explicitly linear skbs; see virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G vhost-transport may allocate non-linear skbs, but only for sizes that are not considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in virtio_vsock_alloc_skb(). Ensure only linear skbs are coalesced. Note that skb_tailroom(last_skb) > 0 guarantees last_skb is linear.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 581512a6dc939ef122e49336626ae159f3b8a345 , < 568e9cd8ed7ca9bf748c7687ba6501f29d30e59f (git)
Affected: 581512a6dc939ef122e49336626ae159f3b8a345 , < 63ef9b300bd09e24c57050c5dbe68feedce42e72 (git)
Affected: 581512a6dc939ef122e49336626ae159f3b8a345 , < 0386bd321d0f95d041a7b3d7b07643411b044a96 (git)
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Linux Linux Affected: 6.7
Unaffected: 0 , < 6.7 (semver)
Unaffected: 6.12.68 , ≤ 6.12.* (semver)
Unaffected: 6.18.8 , ≤ 6.18.* (semver)
Unaffected: 6.19 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/vmw_vsock/virtio_transport_common.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "568e9cd8ed7ca9bf748c7687ba6501f29d30e59f",
              "status": "affected",
              "version": "581512a6dc939ef122e49336626ae159f3b8a345",
              "versionType": "git"
            },
            {
              "lessThan": "63ef9b300bd09e24c57050c5dbe68feedce42e72",
              "status": "affected",
              "version": "581512a6dc939ef122e49336626ae159f3b8a345",
              "versionType": "git"
            },
            {
              "lessThan": "0386bd321d0f95d041a7b3d7b07643411b044a96",
              "status": "affected",
              "version": "581512a6dc939ef122e49336626ae159f3b8a345",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/vmw_vsock/virtio_transport_common.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.68",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.68",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.8",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: Coalesce only linear skb\n\nvsock/virtio common tries to coalesce buffers in rx queue: if a linear skb\n(with a spare tail room) is followed by a small skb (length limited by\nGOOD_COPY_LEN = 128), an attempt is made to join them.\n\nSince the introduction of MSG_ZEROCOPY support, assumption that a small skb\nwill always be linear is incorrect. In the zerocopy case, data is lost and\nthe linear skb is appended with uninitialized kernel memory.\n\nOf all 3 supported virtio-based transports, only loopback-transport is\naffected. G2H virtio-transport rx queue operates on explicitly linear skbs;\nsee virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G\nvhost-transport may allocate non-linear skbs, but only for sizes that are\nnot considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in\nvirtio_vsock_alloc_skb().\n\nEnsure only linear skbs are coalesced. Note that skb_tailroom(last_skb) \u003e 0\nguarantees last_skb is linear."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:59:10.131Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/568e9cd8ed7ca9bf748c7687ba6501f29d30e59f"
        },
        {
          "url": "https://git.kernel.org/stable/c/63ef9b300bd09e24c57050c5dbe68feedce42e72"
        },
        {
          "url": "https://git.kernel.org/stable/c/0386bd321d0f95d041a7b3d7b07643411b044a96"
        }
      ],
      "title": "vsock/virtio: Coalesce only linear skb",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23057",
    "datePublished": "2026-02-04T16:07:40.550Z",
    "dateReserved": "2026-01-13T15:37:45.951Z",
    "dateUpdated": "2026-05-11T21:59:10.131Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-23057",
      "date": "2026-09-16",
      "epss": "0.00172",
      "percentile": "0.06945"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-23057\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-02-04T17:16:16.380\",\"lastModified\":\"2026-06-17T10:20:47.133\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nvsock/virtio: Coalesce only linear skb\\n\\nvsock/virtio common tries to coalesce buffers in rx queue: if a linear skb\\n(with a spare tail room) is followed by a small skb (length limited by\\nGOOD_COPY_LEN = 128), an attempt is made to join them.\\n\\nSince the introduction of MSG_ZEROCOPY support, assumption that a small skb\\nwill always be linear is incorrect. In the zerocopy case, data is lost and\\nthe linear skb is appended with uninitialized kernel memory.\\n\\nOf all 3 supported virtio-based transports, only loopback-transport is\\naffected. G2H virtio-transport rx queue operates on explicitly linear skbs;\\nsee virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G\\nvhost-transport may allocate non-linear skbs, but only for sizes that are\\nnot considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in\\nvirtio_vsock_alloc_skb().\\n\\nEnsure only linear skbs are coalesced. Note that skb_tailroom(last_skb) \u003e 0\\nguarantees last_skb is linear.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\\n\\nvsock/virtio: Coalescer solo skb lineal\\n\\nEl com\u00fan de vsock/virtio intenta coalescer b\u00faferes en la cola rx: si un skb lineal (con espacio de cola libre) es seguido por un skb peque\u00f1o (longitud limitada por GOOD_COPY_LEN = 128), se intenta unirlos.\\n\\nDesde la introducci\u00f3n del soporte MSG_ZEROCOPY, la suposici\u00f3n de que un skb peque\u00f1o siempre ser\u00e1 lineal es incorrecta. En el caso de zerocopy, se pierden datos y el skb lineal es anexado con memoria del kernel no inicializada.\\n\\nDe todos los 3 transportes basados en virtio soportados, solo el transporte loopback se ve afectado. La cola rx del transporte virtio G2H opera con skbs expl\u00edcitamente lineales; ver virtio_vsock_alloc_linear_skb() en virtio_vsock_rx_fill(). El transporte vhost H2G puede asignar skbs no lineales, pero solo para tama\u00f1os que no se consideran para la coalescencia; ver PAGE_ALLOC_COSTLY_ORDER en virtio_vsock_alloc_skb().\\n\\nAsegurar que solo los skbs lineales sean coalescidos. Tenga en cuenta que skb_tailroom(last_skb) \u0026gt; 0 garantiza que last_skb es lineal.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/vmw_vsock/virtio_transport_common.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"581512a6dc939ef122e49336626ae159f3b8a345\",\"lessThan\":\"568e9cd8ed7ca9bf748c7687ba6501f29d30e59f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"581512a6dc939ef122e49336626ae159f3b8a345\",\"lessThan\":\"63ef9b300bd09e24c57050c5dbe68feedce42e72\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"581512a6dc939ef122e49336626ae159f3b8a345\",\"lessThan\":\"0386bd321d0f95d041a7b3d7b07643411b044a96\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/vmw_vsock/virtio_transport_common.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.7\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.7\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.68\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.8\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.19\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0386bd321d0f95d041a7b3d7b07643411b044a96\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/568e9cd8ed7ca9bf748c7687ba6501f29d30e59f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/63ef9b300bd09e24c57050c5dbe68feedce42e72\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-28T07:18:25+00:00",
      "cve": "CVE-2026-23057",
      "id": "CVE-2026-23057",
      "initial_release_date": "2026-02-04T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: vsock/virtio: Coalesce only linear skb",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23057.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

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.


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.