{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-43128",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-43128"
  ],
  "published": "2026-05-06T11:29:17Z",
  "summary": "RDMA/umem: Fix double dma_buf_unpin in failure path",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/umem: Fix double dma_buf_unpin in failure path\n\nIn ib_umem_dmabuf_get_pinned_with_dma_device(), the call to\nib_umem_dmabuf_map_pages() can fail. If this occurs, the dmabuf\nis immediately unpinned but the umem_dmabuf->pinned flag is still\nset. Then, when ib_umem_release() is called, it calls\nib_umem_dmabuf_revoke() which will call dma_buf_unpin() again.\n\nFix this by removing the immediate unpin upon failure and just let\nthe ib_umem_release/revoke path handle it. This also ensures the\nproper unmap-unpin unwind ordering if the dmabuf_map_pages call\nhappened to fail due to dma_resv_wait_timeout (and therefore has\na non-NULL umem_dmabuf->sgt).",
  "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": "6.1.165",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-43128"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/70542b69abff34d24b11ae0bb200cc7a766d18df"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b324327ff6f48d8065dca67eb3b91357e72726bd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ba3bf0f1bf1d5d0404678485e872980532fcc2c4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d3e32e2f3262f1b25d77c085ace38e2cc4ad75cf"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/40126bcbefa79ea86672e05dae608596bab38319"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/104016eb671e19709721c1b0048dd912dc2e96be"
    }
  ],
  "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": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The vulnerable path is reached through local RDMA uverbs ioctls such as dma-buf MR/CQ/DevX registration on /dev/infiniband/uverbs*, with a user-supplied dma-buf fd.\nAC:L - The attacker controls the ioctl inputs and dma-buf fd and can repeatedly drive the failure path after dma_buf_pin() succeeds; no uncontrollable race is required.\nPR:L - The uverbs device nodes are created mode 0666 and the relevant paths do not require CAP_* privileges, but the attacker still needs local unprivileged code execution and access to the device files.\nUI:N - No victim action is needed once the local attacker can issue the uverbs ioctl sequence.\nS:U - The impact remains within the kernel/device memory management security authority; this is not a VM escape or distinct authorization-domain boundary crossing.\nC:H - The double unpin can prematurely drop the exporter pin count while another active mapping of the same dma-buf still exists, allowing stale RDMA DMA mappings to read memory after the buffer is moved or reused.\nI:H - The same stale DMA mapping scenario can allow writes into moved or reused physical pages, giving a plausible high-impact memory corruption primitive.\nA:H - At minimum the double unpin reaches exporter/TTM WARN paths and corrupted pin/accounting state; with panic_on_warn or resulting stale-DMA corruption this can crash or destabilize the kernel."
    }
  }
}