{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89528",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-89528"
  ],
  "published": "2026-09-11T19:47:07Z",
  "summary": "svcrdma: Reject Read lists that exceed the page budget",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject Read lists that exceed the page budget\n\nIndividual Read segment lengths are validated at decode time, but\nnothing prevents a requester from sending multiple segments whose\ncumulative length exceeds the rq_pages array budget. When one\nsegment fills the page array exactly, the runtime guard in\nsvc_rdma_build_read_segment() is bypassed because len reaches zero.\nA subsequent segment then accesses the NULL sentinel slot at\nrq_pages[rq_maxpages], resulting in a NULL pointer dereference during\nDMA mapping.\n\nAccumulate pages across all Read segments and reject the message at\ndecode time when the total would overflow the page budget.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-2026-89528"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1a3af2262cb384112ef38632de4690682be528b4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/465f511f59a0fa7a80d5d1073c4b24f28ea38f58"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0ca487abb3bdf581851664b5db21f364caf57682"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-13T06:49:25Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.5,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - svcrdma is nfsd's RPC-over-RDMA server transport; a remote peer reaches svc_rdma_recvfrom() by sending a Call with a Read list on an enabled NFS/RDMA listener over routable RoCEv2 or iWARP.\nAC:L - The attacker fully controls Read-segment lengths in the transport header and can deterministically fill rq_pages exactly, then send a further segment so the len==0 overrun guard is skipped and the NULL sentinel is DMA-mapped, with no race or uncontrollable layout.\nPR:N - xdr_count_read_segments() and svc_rdma_build_read_segment() run in svc_rdma_recvfrom() while assembling the transport message, before svc_process() performs RPC or NFS authentication, and RDMA CM accept has no credential check.\nUI:N - Sending a crafted RPC-over-RDMA message with an over-budget Read list is sufficient; no victim mount, click, or other user action is required.\nS:U - The NULL dereference oops stays in the host kernel that owns nfsd/svcrdma; this is not a VM, IOMMU, or sandbox escape.\nC:N - The fault is a NULL pointer dereference of the rq_pages[rq_maxpages] sentinel during DMA mapping; the access faults immediately and does not disclose kernel memory.\nI:N - The sentinel slot is a guaranteed NULL page pointer, not an out-of-bounds page used as a write destination; DMA mapping aborts on the NULL page without an arbitrary-write or control-flow hijack primitive.\nA:H - DMA mapping the NULL sentinel produces a kernel oops or panic that an unauthenticated NFS/RDMA peer can trigger repeatedly."
    }
  }
}
