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CVE-2026-80989 (GCVE-0-2026-80989)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:42 – Updated: 2026-09-14 11:59
VLAI
Title
net: thunderbolt: Mark the connection down when bringing it up fails
Summary
In the Linux kernel, the following vulnerability has been resolved: net: thunderbolt: Mark the connection down when bringing it up fails Every failure path in tbnet_connected_work() undoes its own work and returns without clearing login_sent, so the connection still looks established. The next tbnet_tear_down() therefore takes its main branch and repeats a teardown that already happened: it stops rings that are already stopped, which is a dev_WARN() and fatal under panic_on_warn, and it releases net->remote_transmit_path even on the HopID mismatch path, where this connection never owned that id, silently freeing one that someone else is still using. Clear login_sent on those paths. That is enough for tbnet_tear_down() to leave the unwound state alone, and login_received has to stay set: it records that the peer has logged in and carries the transmit path it gave us, which nothing on this side can make the peer send again. Two things change beyond keeping the teardown out of the way: the logout request in that block is no longer sent, and the peer's next login request now re-queues our login work rather than connected_work, giving the connection a fresh login instead of a retry on stale state.
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e , < e0d4a17afde5aa0045dc3e1d66c6bb80927bad8c (git)
Affected: e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e , < ed1d6e3d735e7b03f43a02f4306c89eb7663da14 (git)
Affected: e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e , < f01e6a35c440b62f060e21f36b385e574a7f308c (git)
Affected: e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e , < d6c0af293129345a17dc31c9b4179dc7f3d6af7a (git)
Affected: e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e , < 3c8b26ebf525ba5960510f48c6e9936a79ebe76f (git)
guessed Create a notification for this product.
Linux Linux Affected: 4.15
Unaffected: 0 , < 4.15 (semver)
Unaffected: 6.6.157 , ≤ 6.6.* (semver)
Unaffected: 6.12.109 , ≤ 6.12.* (semver)
Unaffected: 6.18.50 , ≤ 6.18.* (semver)
Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: thunderbolt: Mark the connection down when bringing it up fails\n\nEvery failure path in tbnet_connected_work() undoes its own work and\nreturns without clearing login_sent, so the connection still looks\nestablished. The next tbnet_tear_down() therefore takes its main branch\nand repeats a teardown that already happened: it stops rings that are\nalready stopped, which is a dev_WARN() and fatal under panic_on_warn,\nand it releases net-\u003eremote_transmit_path even on the HopID mismatch\npath, where this connection never owned that id, silently freeing one\nthat someone else is still using.\n\nClear login_sent on those paths. That is enough for tbnet_tear_down() to\nleave the unwound state alone, and login_received has to stay set: it\nrecords that the peer has logged in and carries the transmit path it gave\nus, which nothing on this side can make the peer send again. Two things\nchange beyond keeping the teardown out of the way: the logout request in\nthat block is no longer sent, and the peer\u0027s next login request now\nre-queues our login work rather than connected_work, giving the\nconnection a fresh login instead of a retry on stale state."
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              "value": "AV:A - Triggered by ThunderboltIP XDomain control messages (TBIP_LOGIN/TBIP_LOGOUT) from a peer on the same direct Thunderbolt/USB4 link; not Internet-routable, but reachable from an adjacent connected host, dock, or in-line device, matching other tbnet CVEs.\nAC:L - A malicious peer completes the ThunderboltIP handshake, sends LOGIN with an invalid or colliding transmit_path so tbnet_connected_work() fails, then sends TBIP_LOGOUT to run tbnet_tear_down(); the attacker controls both sides with no race or layout dependency.\nPR:N - No Linux account, capability, or init-namespace privilege is required; any Thunderbolt/USB4 peer that speaks ThunderboltIP can send the crafted login and logout on the unauthenticated XDomain control channel after the automatic host-to-host handshake.\nUI:N - Once a ThunderboltIP-capable link exists, which is typical for docks, direct laptop-to-laptop networking, and shared workstations, the peer can force the failed bring-up and teardown without further victim action beyond the existing cable connection.\nS:U - Impact stays in the host kernel Thunderbolt network driver and XDomain DMA path state (ring WARN, HopID IDA, NHI teardown) and does not by itself cross a VM, container, or IOMMU security boundary.\nC:H - Failed bring-up leaves login_sent set, so the next teardown releases net-\u003eremote_transmit_path even when this connection never owned that HopID, freeing an ID another tunnel still uses; reuse of that HopID can misdirect NHI DMA and disclose kernel or other-tunnel buffer contents.\nI:H - The same stale-login teardown double-stops rings and disables or releases DMA HopIDs that may belong to another XDomain tunnel, and on ICM firmware it issues a port-wide XDomain disconnect, which can overwrite live hop config and let reused NHI DMA corrupt kernel memory.\nA:H - Repeating teardown of an already unwound connection calls tb_ring_stop() on stopped rings (dev_WARN, fatal under panic_on_warn) and ida_free() of an unallocated or in-use HopID (WARN), and can hang or panic the host via bad DMA path teardown."
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    "datePublished": "2026-09-11T19:42:46.872Z",
    "dateReserved": "2026-08-26T14:34:25.811Z",
    "dateUpdated": "2026-09-14T11:59:31.013Z",
    "state": "PUBLISHED"
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      "initial_release_date": "2026-09-13T01:05:49.000Z",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
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    "redhat_vex": {
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      "current_release_date": "2026-09-14T20:05:57+00:00",
      "cve": "CVE-2026-80989",
      "id": "CVE-2026-80989",
      "initial_release_date": "2026-09-11T00:00:00+00:00",
      "product_status:known_affected": "234",
      "product_status:known_not_affected": "42",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net: thunderbolt: Mark the connection down when bringing it up fails",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80989.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-15T01:04:36Z",
      "cve": "CVE-2026-80989",
      "id": "CVE-2026-80989",
      "initial_release_date": "2026-09-15T01:04:36Z",
      "product_status:known_affected": "263",
      "product_status:known_not_affected": "90",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80989",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80989.json",
      "version": "2"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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