{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80987",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80987"
  ],
  "published": "2026-09-11T19:47:07Z",
  "summary": "NTB: ntb_transport: Reject oversized TX buffers",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNTB: ntb_transport: Reject oversized TX buffers\n\nntb_process_tx() handles an oversized buffer by calling tx_handler()\nwith a NULL data pointer and returning success. ntb_netdev therefore\nneither frees the skb in its completion callback nor takes its enqueue\nerror path, leaking it.\n\nReject oversized buffers in ntb_transport_tx_enqueue() before acquiring\na queue entry and return -EMSGSIZE. The caller retains ownership of the\nbuffer, and the preceding netdev patch frees the skb when enqueue\nreturns this permanent error.",
  "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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80987"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4890152a3069f5cb58cc24b08cfd5fe95e568fa1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/668aa3238548584ca9772da9cf43ae8c2389bbf1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9b0fa8a9e1057614a533cc3f18b17f82aab028d8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b6db88cde0fb5c3bd2d3cd2bebcc06b5ce146e88"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a7f22105a7df8c7fd74d0af27ace6fa94fe03d87"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6b6bbc6c878d64eacc60877df49fce7b1b6a08d0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/75a604e9f1cfdebda421062fdf42225ca32154cd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a4f2387db6f1cc2f03abba7f3a6807ad61e26ff7"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-14T12:06:03Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.5,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - ntb_transport_tx_enqueue() is reached from ntb_netdev_start_xmit() on the NTB virtual Ethernet device; in dual-controller/cluster deployments that interconnect carries routed or 802.1Q traffic, so a remote peer can induce full-MTU egress (software VLAN insertion adds VLAN_HLEN past the transport payload limit) without local access.\nAC:L - Any TX buffer longer than tx_max_frame minus the payload header deterministically takes the oversized path; VLAN devices default to the lowerdev MTU so tagged full-size frames always exceed the limit, and AF_PACKET allows MTU+VLAN_HLEN, with no race or uncontrolled layout.\nPR:N - The netdev TX path has no authentication or capability check; once the NTB link is up, any host exchanging traffic over the interconnect or a VLAN/service on it can cause oversized transmits without credentials on the victim.\nUI:N - Oversized frames are transmitted by the kernel networking stack during ordinary packet egress; no victim action such as mounting a device or opening a file is required.\nS:U - The defect leaks sk_buff memory on the transmitting host inside the same kernel authority; it is not a VM escape, IOMMU/DMA bypass, or corruption of the peer host over the NTB link.\nC:N - The oversized path never copies payload bytes and does not free or reuse the skb, so there is no out-of-bounds read, use-after-free, or other information-disclosure primitive.\nI:N - ntb_process_tx() refuses to DMA or memcpy an oversized buffer and only invokes the completion callback with a NULL pointer, so there is no out-of-bounds write, heap corruption, or control-flow hijacking.\nA:H - Enqueue returns success while the TX handler is called with a NULL skb and skips kfree, permanently leaking one sk_buff (and its pages/socket accounting) per oversized transmit; repeating this exhausts kernel memory and causes OOM denial of service."
    }
  }
}