{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-92507",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-92507"
  ],
  "published": "2026-09-17T16:10:40Z",
  "summary": "RDMA/core: Fix potential use after free in ib_dealloc_pd_user()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/core: Fix potential use after free in ib_dealloc_pd_user()\n\nWhen accessing a PD via the netlink path the only synchronization\nmechanism for the said PD is rdma_restrack_get().\nCurrently, rdma_restrack_del() is invoked at the end of\nib_dealloc_pd_user(), which is too late, since by that point\nvendor-specific resources associated with the PD might already be\nfreed. This can leave a short window where the PD remains accessible\nthrough restrack, leading to a potential use-after-free.\n\nFix this by moving the rdma_restrack_begin_del() call to the start of\nib_dealloc_pd_user(), ensuring that the PD is removed from restrack\nbefore its internal resources are released. This guarantees that no new\nusers hold references to a PD that is in the process of destruction.\n\nIn addition, this change preserves the intended inverted order\nbetween create and destroy routines: resources are added to\nrestrack at the end of successful creation, and hence shall be removed\nfrom the restrack first thing during the destruction flow, which keeps\nthe lifecycle management consistent and predictable.",
  "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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-92507"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/df0e9efe61ca706a07b1c9bf93fcb9032455efc4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7647363fa02046da681acc3c827d9f301c06e0e7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d9c0daf9362aad2aeed1d9c5536d108772a8d31c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/66d65f36d39759e9f62dc746dc71d862f20f827f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c06f2856a1d7e75a5ff247fc05224aa2452e7265"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8b90e701342275f414e36e7421c502237df241ad"
    }
  ],
  "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 race is between ib_uverbs_dealloc_pd()/uverbs_free_pd() (IB_USER_VERBS_CMD_DEALLOC_PD or UVERBS_METHOD_PD_DESTROY on /dev/infiniband/uverbs*) and nldev_res_get_pd_dumpit()/nldev_res_get_pd_doit() via NETLINK_RDMA RDMA_NLDEV_CMD_RES_PD_GET. Those syscalls supply the destroy and the dump; no remote protocol message carries the malformed state.\nAC:L - The attacker runs both sides: one thread deallocates its PD while another loops RDMA_NLDEV_CMD_RES_PD_GET. res_get_common_dumpit() can rdma_restrack_get() until rdma_restrack_del(), and ops.dealloc_pd() (often a firmware round-trip) sits in that window, so the attacker creates and retries the race.\nPR:L - uverbs_devnode() sets /dev/infiniband/uverbs* to 0666, so an unprivileged process can alloc/dealloc a PD. RDMA_NLDEV_CMD_RES_PD_GET has no RDMA_NL_ADMIN_PERM, and NETLINK_RDMA is created with NL_CFG_F_NONROOT_RECV, so sendmsg to kernel portid 0 does not need CAP_NET_ADMIN.\nUI:N - The attacker opens uverbs, allocates a PD, then concurrently issues IB_USER_VERBS_CMD_DEALLOC_PD and RDMA_NLDEV_CMD_RES_PD_GET; no other user action is required.\nS:U - A successful UAF corrupts memory in ib_core and the RDMA driver on the same host kernel. It does not cross a VM, IOMMU, or other security-authority boundary.\nC:H - ib_dealloc_pd_user() runs dereg_mr(pd->__internal_mr) and ops.dealloc_pd() before rdma_restrack_del(). fill_res_pd_entry() can still rdma_restrack_get() that PD and read pd, including pd->uobject->context. In that window bnxt_re_dealloc_pd() kfree()s fence->mr via bnxt_re_destroy_fence_mr(), so reused driver objects can disclose kernel memory.\nI:H - The same window lets the attacker spray and reuse objects freed inside ops.dealloc_pd() (bnxt_re_destroy_fence_mr() kfree(mr), rxe_cleanup() of the PD pool element) while fill_res_pd_entry() still holds the PD via restrack, which is a kernel write/control-flow hijack primitive.\nA:H - Racing nldev_res_get_pd_dumpit() against ib_dealloc_pd_user() after vendor teardown can oops in fill_res_pd_entry() while it follows pd->uobject->context on a PD whose driver state is already gone, crashing the host."
    }
  }
}