{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "d021c344051af91f42c5ba9fdedc176740cbd238"
            },
            {
              "fixed": "c5a75d37c21e558cc6fad1597e732ead30745eed"
            },
            {
              "fixed": "36e5fa009f98a4edbe1783ac11c0df672b224742"
            },
            {
              "fixed": "491b368a0c6e5f28b615a50b0d384f5c25fde2a7"
            },
            {
              "fixed": "b8c899cf5e7be29840a172c183dedd8d3e7a0287"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.9.0"
            },
            {
              "fixed": "6.12.110"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.52"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90138.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: don't check the listener's sk_err in vsock_accept()\n\nSyzbot reported an issue which can be reproduced with these steps:\n\tr0 = socket(AF_VSOCK, SOCK_STREAM, 0)\n\tbind(r0, {VMADDR_CID_ANY, PORT})\n\tconnect(r0, {VMADDR_CID_LOCAL, PORT}) -\u003e -1, EPROTO (self-connect)\n\tlisten(r0, backlog)                   -\u003e 0\n\tr1 = socket(AF_VSOCK, SOCK_STREAM, 0)\n\tconnect(r1, {VMADDR_CID_LOCAL, PORT}) -\u003e 0\n\taccept(r0)                            -\u003e -1, EPROTO (stale sk_err)\n\nBasically, it creates a socket (r0) and triggers a self-connect after\nbinding it. This self-connect fails with EPROTO because it loops back\nto r0 while the socket is still in the TCP_SYN_SENT state, causing it\nto be incorrectly dispatched to the connecting-client path. The\nunexpected packet type encountered there sets sk_err to EPROTO.\n\nAfter that, it invokes a listen() call on the same socket. This\nlisten() call succeeds because the kernel's listening path never\ninspects or clears sk_err. Then, a new socket (r1) is created as a\nnormal client and connects to r0. However, vsock_accept() rejects this\nincoming connection because the listener's sk_err still holds the\nEPROTO error from the earlier failed self-connect.\n\nThis rejection causes the child socket created for r1's connection to\nnever be freed on virtio or hyperv transports; only the VMCI transport\nimplements pending_work to revisit and clean up a rejected socket.\n\nFor a non-blocking connect(), vsock_connect() may return -EINPROGRESS\nimmediately, and vsock_connect_timeout() can later set sk-\u003esk_err\nasynchronously.\n\nSince no vsock transport ever sets sk_err on a socket while it is in\nTCP_LISTEN state, checking it in vsock_accept() serves no purpose and\nonly carries forward errors left behind by earlier, unrelated\nconnection attempts on the same socket. Remove the checks so accept()\nno longer rejects valid incoming connections because of a stale\nerror, which also avoids the resource leak described above.",
  "id": "CVE-2026-90138",
  "modified": "2026-09-18T03:30:29.574165573Z",
  "published": "2026-09-17T16:06:36.528Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/36e5fa009f98a4edbe1783ac11c0df672b224742"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/491b368a0c6e5f28b615a50b0d384f5c25fde2a7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b8c899cf5e7be29840a172c183dedd8d3e7a0287"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c5a75d37c21e558cc6fad1597e732ead30745eed"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90138.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90138"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "vsock: don't check the listener's sk_err in vsock_accept()"
}