{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-98360",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-98360"
  ],
  "published": "2026-10-06T08:47:10Z",
  "summary": "RDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds\n\nrxe_get_mcg() publishes a newly allocated multicast group in\nrxe->mcg_tree before programming the backing Ethernet multicast address\nwith rxe_mcast_add(), which runs outside mcg_lock. A local userspace\nRDMA client reaches this path with ATTACH_MCAST on a UD QP; if\nrxe_mcast_add() then returns an error (for example -ENODEV when the\nbacking netdev has been removed, or a propagated dev_mc_add() error),\nthe unwind frees the published group without removing it from the tree.\nA later lookup of the same MGID dereferences the freed struct rxe_mcg\nfrom __rxe_lookup_mcg().\n\nFix this by keeping the new mcg private until rxe_mcast_add() succeeds.\nSplit the tree publication into __rxe_publish_mcg(), call rxe_mcast_add()\nbefore taking the tree reference, and free the still-private mcg on\nfailure. Because the group is never visible in mcg_tree until the\nmulticast address is programmed, no concurrent caller can look it up or\nattach a QP to a group that is about to be torn down, so the error path\nneeds no conditional unwind. If another caller publishes the same MGID\nwhile the address is being programmed, the post-add re-check under\nmcg_lock finds the winner; this caller then drops its private object and\nbalances its own rxe_mcast_add() with rxe_mcast_del() before returning\nthe winner.\n\nReproduced by forcing the rxe_mcast_add() error return under KASAN:\nwithout the change the next attach to the same MGID reports a\nslab-use-after-free in __rxe_lookup_mcg(); with it the forced failure\nreturns cleanly. A no-injection attach/detach regression, including a\ntwo-QP shared join/leave and re-attach, stays KASAN- and leak-clean.",
  "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": "6.1.189",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-98360"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ddb43ac0926d4a931bc9b7744b93627f627457e5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c79a789aa15180a1543b5db49c343d12e3ec214d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/faae1fb4ccf8205806a8802c008798dabeb0205b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/02c0a2fa69c16248a7432af8a6d64ab2a73a5283"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d4fc4e37f8a143b0fe83b42c8fb48cf542154fee"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1caceeb2d74bbe88223aea55eb8626b4c5f076fd"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-10-07T06:50:27Z"
  }
}