sctp: check send stream number after wait_for_sndbuf

{
  "id": "e15dbb24c3144e717884220ee90148c33c1a40e8b3b1f9a280091cf798cd9131",
  "url": "https://osv.dev/vulnerability/CVE-2023-53296",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "sctp: check send stream number after wait_for_sndbuf",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: sctp: check send stream number after wait_for_sndbuf This patch fixes a corner case where the asoc out stream count may change after wait_for_sndbuf. When the main thread in the client starts a connection, if its out stream count is set to N while the in stream count in the server is set to N - 2, another thread in the client keeps sending the msgs with stream number N - 1, and waits for sndbuf before processing INIT_ACK. However, after processing INIT_ACK, the out stream count in the client is shrunk to N - 2, the same to the in stream count in the server. The crash occurs when the thread waiting for sndbuf is awake and sends the msg in a non-existing stream(N - 1), the call trace is as below: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] Call Trace: sctp_cmd_send_msg net/sctp/sm_sideeffect.c:1114 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1777 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x197d/0x5310 net/sctp/sm_sideeffect.c:1170 sctp_primitive_SEND+0x9f/0xc0 net/sctp/primitive.c:163 sctp_sendmsg_to_asoc+0x10eb/0x1a30 net/sctp/socket.c:1868 sctp_sendmsg+0x8d4/0x1d90 net/sctp/socket.c:2026 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:825 sock_sendmsg_nosec net/socket.c:722 [inline] sock_sendmsg+0xde/0x190 net/socket.c:745 The fix is to add an unlikely check for the send stream number after the thread wakes up from the wait_for_sndbuf.",
    "evidence": "osv:CVE-2023-53296",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.19.281",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.4.241",
            "evidence": "/affected/1/ranges"
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            "evidence": "/affected/1/ranges"
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            "evidence": "/affected/1/ranges"
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          {
            "value": "6.1.24",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.2.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2023-53296",
      "aliases": [
        "CVE-2023-53296"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
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                {
                  "fixed": "0443fff49d6352160c200064156c25898bd9f58c"
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          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53296.json"
          }
        },
        {
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              "type": "ECOSYSTEM",
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                  "introduced": "4.15.0"
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
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      ],
      "modified": "2026-10-28T02:30:28.378186967Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0443fff49d6352160c200064156c25898bd9f58c",
        "https://git.kernel.org/stable/c/2584024b23552c00d95b50255e47bd18d306d31a",
        "https://git.kernel.org/stable/c/667eb99cf7c15fe5b0ecefe75cf658e20ef20c9f",
        "https://git.kernel.org/stable/c/9346a1a21142357972a6f466ba6275ddc54b04ac",
        "https://git.kernel.org/stable/c/a615e7270318fa0b98bf1ff38daf6cf52d840312",
        "https://git.kernel.org/stable/c/b4b6dfad41aaae9e36e44327b18d5cf4b20dd2ce",
        "https://git.kernel.org/stable/c/d2128636b303aa9cf065055402ee6697409a8837",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53296.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-53296",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53296.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-53296",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 495035,
  "published_at": "2025-09-16T08:11:28.519+00:00"
}