{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-31536",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-31536"
  ],
  "published": "2026-04-24T14:30:42Z",
  "summary": "smb: server: let send_done handle a completion without IB_SEND_SIGNALED",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: server: let send_done handle a completion without IB_SEND_SIGNALED\n\nWith smbdirect_send_batch processing we likely have requests without\nIB_SEND_SIGNALED, which will be destroyed in the final request\nthat has IB_SEND_SIGNALED set.\n\nIf the connection is broken all requests are signaled\neven without explicit IB_SEND_SIGNALED.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-31536"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/24082642654f3e5149913946e89c00a297a8868f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e38b415c024bc3b6321bf8650dbf3f4aab8e74b3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9da82dc73cb03e85d716a2609364572367a5ff47"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 9.8,
      "cvss_v3_severity": "Critical",
      "scenario": "AV:N - The vulnerable code is in ksmbd SMB Direct, which accepts remote RDMA/SMB Direct connections on network ports 445 and 5445 and processes peer-controlled SMB Direct traffic.\nAC:L - An attacker can negotiate a small SMB Direct max receive size to force batched multi-WR sends, then break the connection to make unsignaled sends complete with error. The disconnect/error condition is attacker-controlled rather than an external race.\nPR:N - The path is reachable before SMB authentication: SMB Direct negotiation completes first, and SMB2 NEGOTIATE/SESSION_SETUP do not require a valid session. A pre-auth remote client can trigger outbound responses through the vulnerable RDMA send batching path.\nUI:N - No victim user action is required once ksmbd with SMB Direct is listening; the attacker only needs to connect and send protocol messages.\nS:U - The impact is within the kernel/ksmbd host security authority and does not cross a hypervisor, IOMMU, or separate sandbox boundary.\nC:H - The bug is a use-after-free/double-free style memory corruption in RDMA send objects, and kernel UAFs can be shaped into disclosure primitives through heap reuse.\nI:H - The freed `smbdirect_send_io` objects contain list pointers, CQ callbacks, and work request state; corrupting or reusing them can plausibly support arbitrary write or control-flow hijack.\nA:H - Even without full exploitation, the UAF/list corruption is expected to cause kernel warnings, crashes, or hangs during RDMA QP drain and completion handling."
    }
  }
}