{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-72157",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-72157"
  ],
  "published": "2026-08-15T06:04:33Z",
  "summary": "net: thunderbolt: Fix frags[] overflow by bounding frame_count",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: thunderbolt: Fix frags[] overflow by bounding frame_count\n\ntbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The\nfirst frame goes into the skb linear area and every further frame is added as\na page fragment.\n\n\tskb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,\n\t\t\tpage, hdr_size, frame_size,\n\t\t\tTBNET_RX_PAGE_SIZE - hdr_size);\n\nA packet of frame_count frames therefore ends up with frame_count - 1\nfragments. tbnet_check_frame() only bounds the peer supplied frame_count to\nTBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A\npeer that sends a packet of 19 or more small frames pushes nr_frags past\nMAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and\ncorrupts memory after the shared info.\n\nTighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never\nproduce more fragments than frags[] can hold. This matches the recent skb\nfrags overflow fixes in other receive paths, for example f0813bcd2d9d (\"net:\nwwan: t7xx: fix potential skb->frags overflow in RX path\") and 600dc40554dc\n(\"net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()\").",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/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": "6.1.184",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-72157"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f96b3b35c622d565eff2438993e028d280163f5c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6262f51e09d8dc8b07599a9e4f03bd3989d13fff"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/569ba39b2d12995a29dc158e5b4de6e449278f30"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2b3b4e5ff5a58ad32817824b0310e63908b12052"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e27beb4536cbf1d59e2d8c2840e87d972aba906f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e5824d5b841d99a2bcdd4e2c256643293bbc22c1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fe6b606fbf0c3beb94ccf17fcf31d8c2138264e3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/55d9895f89970501fe126d1026b586b04a224c27"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-23T12:46:35Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 8.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:A - The flaw is triggered by malicious ThunderboltIP frames sent from a peer on the same direct Thunderbolt/USB4 link; exploitation is not Internet-routable but is reachable from an adjacent connected host, dock, or peripheral without local syscall access.\nAC:L - An adjacent peer can reliably trigger the overflow by sending a start-of-packet header with frame_count of 19-64 and delivering the matching small frames; no races or attacker-uncontrollable heap layout are required.\nPR:N - The attacker needs no account, capability, or privilege on the victim OS; a malicious Thunderbolt/USB4 peer that completes XDomain ThunderboltIP login can send the crafted RX frames directly over the established DMA path.\nUI:N - Once a ThunderboltIP session is active, which is common with docks, direct laptop-to-laptop links, and shared workstations, triggering the bug requires no further victim action beyond the existing link.\nS:U - Memory corruption occurs in the kernel Thunderbolt network driver during skb reassembly and does not by itself cross a VM, container, or IOMMU security boundary.\nC:H - skb_add_rx_frag() writes past skb_shinfo()->frags[], corrupting adjacent kernel memory; such out-of-bounds skb metadata corruption is reasonably leverageable for information disclosure as well as further exploitation.\nI:H - The overflow is an attacker-controlled out-of-bounds write of skb fragment descriptors beyond MAX_SKB_FRAGS, which can corrupt heap/skb metadata and be developed into arbitrary kernel memory modification or code execution.\nA:H - Corrupting memory past skb_shared_info can cause kernel oopses, panics, or unstable behavior during RX processing, and repeated malicious packets can deny service on affected systems."
    }
  }
}