{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-90308",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-90308"
  ],
  "published": "2026-09-17T16:10:40Z",
  "summary": "RDMA/erdma: Hold QP references for AE and CM processing",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/erdma: Hold QP references for AE and CM processing\n\nAE QP fatal events and iWARP CM paths load QPs from dev->qp_xa\nand then use or reference them outside the xarray lock.\nerdma_destroy_qp() can drop the destroy-path reference and free QP\nresources while such a lookup is in flight.\n\nAdd erdma_qp_get_by_qpn() to acquire a kref under the xarray\nlock with kref_get_unless_zero(). Remove the QP from the xarray\nbefore dropping the destroy-path reference so no new lookup can acquire\nit while destruction waits for existing users.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/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-2026-90308"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6e32f84b63c054e09392153125d7202abab2d14b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ec987c0654651036dad6a42f7fa2a6d7c16a3687"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c92686867638cda954fdb2bdbac8a75e3aa6eaae"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a52eeff32024f190b3bdc99088c7becccd4fa60b"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-18T17:55:42Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The UAF is a race between local ib_uverbs_destroy_qp()->erdma_destroy_qp() dropping the QP kref and either ucma_connect()/ucma_accept() (RDMA_USER_CM_CONNECT/ACCEPT -> iw_cm_connect()/iw_cm_accept() -> erdma_connect()/erdma_accept() xa_load of userspace params->qpn) or erdma_comm_irq_handler()->erdma_aeq_event_handler(). The CM QPN is rdma_ucm_conn_param.qp_num, not a remote iWARP/RoCE field.\nAC:L - The attacker who created the QP drives both sides: one thread issues ucma_connect()/ucma_accept() or QP ops that produce an AEQE, while another calls ib_uverbs_destroy_qp(), racing find_qp_by_qpn()/xa_load against the destroy-path erdma_qp_put(). The window (bare xa_load, then kref_get or no get at all) can be retried across many QPs.\nPR:L - ib_uverbs_open() and ucma_open() perform no capability check; uverbs_devnode() and ucma_misc.mode publish /dev/infiniband/uverbs* and /dev/infiniband/rdma_cm as 0666, so an unprivileged user on an ERDMA host can create_qp, RDMA_USER_CM_CONNECT/ACCEPT, and destroy_qp.\nUI:N - The attacker creates the QP via uverbs, issues ucma_connect()/ucma_accept() (or generates an AEQE) and ib_uverbs_destroy_qp() from their own processes; no other user must mount, open, or otherwise act.\nS:U - The use-after-free is of the host kernel's struct erdma_qp (kref, ibqp.event_handler, queue buffers) under the same kernel authority and does not cross a VM, IOMMU, or guest-host boundary.\nC:H - After erdma_destroy_qp() drops the last kref and the RDMA core frees the QP, erdma_aeq_event_handler() still reads qp->ibqp.event_handler and qp_context from the freed object, and erdma_connect() may kref_get a freed QP; a sprayed replacement yields a kernel-memory read primitive.\nI:H - erdma_aeq_event_handler() invokes qp->ibqp.event_handler on the freed erdma_qp, and erdma_connect()/erdma_accept() write qp->cep and take qp->state_lock after a lockless xa_load; reclaiming that object gives a function-pointer call and kernel writes.\nA:H - Using the QP after erdma_qp_put()/wait_for_completion() has released its queues and the ib_qp object causes a kernel oops or panic in erdma_aeq_event_handler() or in erdma_connect()/erdma_accept()."
    }
  }
}