CVE-2026-99216

Full vulnerability record from the local CVENow database.

Description

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.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-28 11:17:43.160000

Last modified

2026-10-28 11:17:43.160000

View original CVE JSON

{
  "id": "CVE-2026-99216",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-28T11:17:43.160",
  "lastModified": "2026-10-28T11:17:43.160",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nDrivers: hv: Don't 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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/hv/connection.c",
            "drivers/hv/vmbus_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "74347a99e73ae00b8385f1209aaea193c670f901",
              "lessThan": "f47ce27af80b87cc684d5c12b65506af498ac7e5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "74347a99e73ae00b8385f1209aaea193c670f901",
              "lessThan": "3195546a377c2d8d176d837e8baad5ce15d11195",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "74347a99e73ae00b8385f1209aaea193c670f901",
              "lessThan": "ec31dc39e835ccde0930daccece8c492d28282fc",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5e059fc0f054309036d3f612bc8b0a502ca58545",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "9f38f7b46de0747c1909e8c557aa21715dce20c5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "caeeb3787167c884b955404a7e669fd77f267e44",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4.19.118",
              "lessThan": "4.20",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "5.4.35",
              "lessThan": "5.5",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "5.6.7",
              "lessThan": "5.7",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/hv/connection.c",
            "drivers/hv/vmbus_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.7",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.7",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.59",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.13",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3195546a377c2d8d176d837e8baad5ce15d11195",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ec31dc39e835ccde0930daccece8c492d28282fc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f47ce27af80b87cc684d5c12b65506af498ac7e5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}