---
id: CVE-2026-72157
title: 'net: thunderbolt: Fix frags[] overflow by bounding frame_count'
summary: |-
  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 sk…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    f96b3b35c622d565eff2438993e028d280163f5c
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    6262f51e09d8dc8b07599a9e4f03bd3989d13fff
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    569ba39b2d12995a29dc158e5b4de6e449278f30
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    2b3b4e5ff5a58ad32817824b0310e63908b12052
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    e27beb4536cbf1d59e2d8c2840e87d972aba906f
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    e5824d5b841d99a2bcdd4e2c256643293bbc22c1
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    fe6b606fbf0c3beb94ccf17fcf31d8c2138264e3
  - >-
    Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e <
    55d9895f89970501fe126d1026b586b04a224c27
  - Linux 4.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:42:59.492495Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T18:44:59.473Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-72157'
references:
  - url: 'https://git.kernel.org/stable/c/f96b3b35c622d565eff2438993e028d280163f5c'
  - url: 'https://git.kernel.org/stable/c/6262f51e09d8dc8b07599a9e4f03bd3989d13fff'
  - url: 'https://git.kernel.org/stable/c/569ba39b2d12995a29dc158e5b4de6e449278f30'
  - url: 'https://git.kernel.org/stable/c/2b3b4e5ff5a58ad32817824b0310e63908b12052'
  - url: 'https://git.kernel.org/stable/c/e27beb4536cbf1d59e2d8c2840e87d972aba906f'
  - url: 'https://git.kernel.org/stable/c/e5824d5b841d99a2bcdd4e2c256643293bbc22c1'
  - url: 'https://git.kernel.org/stable/c/fe6b606fbf0c3beb94ccf17fcf31d8c2138264e3'
  - url: 'https://git.kernel.org/stable/c/55d9895f89970501fe126d1026b586b04a224c27'
tags:
  - cve.org
epss: 0.00345
epssPercentile: 0.26416
ingestedAt: '2026-10-16T19:46:24.426Z'
---

## Overview

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()").

## Affected

- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < f96b3b35c622d565eff2438993e028d280163f5c`
- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < 6262f51e09d8dc8b07599a9e4f03bd3989d13fff`
- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < 569ba39b2d12995a29dc158e5b4de6e449278f30`
- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < 2b3b4e5ff5a58ad32817824b0310e63908b12052`
- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < e27beb4536cbf1d59e2d8c2840e87d972aba906f`
- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < e5824d5b841d99a2bcdd4e2c256643293bbc22c1`
- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < fe6b606fbf0c3beb94ccf17fcf31d8c2138264e3`
- `Linux >= e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e < 55d9895f89970501fe126d1026b586b04a224c27`
- `Linux 4.15`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.