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GHSA-8F5R-C72F-67G5

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-23 15:33
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

net: thunderbolt: Fix frags[] overflow by bounding frame_count

tbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The first frame goes into the skb linear area and every further frame is added as a page fragment.

skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
        page, hdr_size, frame_size,
        TBNET_RX_PAGE_SIZE - hdr_size);

A packet of frame_count frames therefore ends up with frame_count - 1 fragments. tbnet_check_frame() only bounds the peer supplied frame_count to TBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A peer that sends a packet of 19 or more small frames pushes nr_frags past MAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and corrupts memory after the shared info.

Tighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never produce more fragments than frags[] can hold. This matches the recent skb frags overflow fixes in other receive paths, for example f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") and 600dc40554dc ("net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()").

Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-72157"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:21:33Z",
    "severity": "HIGH"
  },
  "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)-\u003enr_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()-\u003efrags[] 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-\u003efrags overflow in RX path\") and 600dc40554dc\n(\"net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()\").",
  "id": "GHSA-8f5r-c72f-67g5",
  "modified": "2026-08-23T15:33:00Z",
  "published": "2026-08-15T06:32:14Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72157"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b3b4e5ff5a58ad32817824b0310e63908b12052"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55d9895f89970501fe126d1026b586b04a224c27"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/569ba39b2d12995a29dc158e5b4de6e449278f30"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6262f51e09d8dc8b07599a9e4f03bd3989d13fff"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e27beb4536cbf1d59e2d8c2840e87d972aba906f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e5824d5b841d99a2bcdd4e2c256643293bbc22c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f96b3b35c622d565eff2438993e028d280163f5c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fe6b606fbf0c3beb94ccf17fcf31d8c2138264e3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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