CVE-2026-99216 (GCVE-0-2026-99216)
Vulnerability from cvelistv5
Published
2026-10-28 10:36
Modified
2026-10-28 10:36
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: Don't reset VMBus connection state on error/exit paths In two places, current code forces vmbus_connection.conn_state to DISCONNECTED prior to calling vmbus_disconnect(). But vmbus_disconnect() calls vmbus_initiate_unload(), which unloads the VMBus connection only if the conn_state is CONNECTED. Consequently, the connection remains and the Hyper-V host might continue to send messages or post VMBus interrupts. The problem was introduced in commit 74347a99e73ae ("x86/Hyper-V: Unload vmbus channel in hv panic callback"), in that vmbus_initiate_unload() started checking the current connection state before doing the unload. This commit removed some occurrences where conn_state was forced to DISCONNECTED, but these two remained, apparently due to an oversight at the time. Fix this by not forcing conn_state to DISCONNECTED during VMBus exit, or if a failure occurs when establishing the connection in the first place. Whatever value conn_state has at the time is then read by vmbus_initiate_unload() to determine if there is a connection to be unloaded.
References
Impacted products
Vendor Product Version
Linux Linux Version: 74347a99e73ae00b8385f1209aaea193c670f901
Version: 74347a99e73ae00b8385f1209aaea193c670f901
Version: 74347a99e73ae00b8385f1209aaea193c670f901
Version: 5e059fc0f054309036d3f612bc8b0a502ca58545
Version: 9f38f7b46de0747c1909e8c557aa21715dce20c5
Version: caeeb3787167c884b955404a7e669fd77f267e44
Version: 4.19.118   ≤
Version: 5.4.35   ≤
Version: 5.6.7   ≤
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hv/connection.c",
            "drivers/hv/vmbus_drv.c"
          ],
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          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/hv/connection.c",
            "drivers/hv/vmbus_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "5.7"
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              "status": "unaffected",
              "version": "0",
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              "status": "unaffected",
              "version": "6.18.59",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.13",
              "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": "6.18.59",
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                  "vulnerable": true
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                  "versionEndExcluding": "7.2.13",
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              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nDrivers: hv: Don\u0027t reset VMBus connection state on error/exit paths\n\nIn two places, current code forces vmbus_connection.conn_state to\nDISCONNECTED prior to calling vmbus_disconnect(). But vmbus_disconnect()\ncalls vmbus_initiate_unload(), which unloads the VMBus connection\nonly if the conn_state is CONNECTED. Consequently, the connection\nremains and the Hyper-V host might continue to send messages or post\nVMBus interrupts.\n\nThe problem was introduced in commit 74347a99e73ae (\"x86/Hyper-V:\nUnload vmbus channel in hv panic callback\"), in that\nvmbus_initiate_unload() started checking the current connection\nstate before doing the unload. This commit removed some occurrences\nwhere conn_state was forced to DISCONNECTED, but these two remained,\napparently due to an oversight at the time.\n\nFix this by not forcing conn_state to DISCONNECTED during VMBus exit,\nor if a failure occurs when establishing the connection in the first\nplace. Whatever value conn_state has at the time is then read by\nvmbus_initiate_unload() to determine if there is a connection to\nbe unloaded."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-28T10:36:09.383Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f47ce27af80b87cc684d5c12b65506af498ac7e5"
        },
        {
          "url": "https://git.kernel.org/stable/c/3195546a377c2d8d176d837e8baad5ce15d11195"
        },
        {
          "url": "https://git.kernel.org/stable/c/ec31dc39e835ccde0930daccece8c492d28282fc"
        }
      ],
      "title": "Drivers: hv: Don\u0027t reset VMBus connection state on error/exit paths",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-99216",
    "datePublished": "2026-10-28T10:36:09.383Z",
    "dateReserved": "2026-09-25T10:25:14.401Z",
    "dateUpdated": "2026-10-28T10:36:09.383Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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