CVE-2026-80989
Received Received - Intake

Thunderbolt Network Connection Failure in Linux Kernel

Vulnerability report for CVE-2026-80989, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

Description

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.

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Meta Information

Published
2026-09-11
Last Modified
2026-09-11
Generated
2026-09-12
AI Q&A
2026-09-12
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

CWE
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel occurs when bringing up a Thunderbolt network connection fails. The system fails to properly reset the connection state, leaving it marked as established even though it failed. This causes issues during teardown, potentially stopping already stopped rings and releasing resources incorrectly.

Impact Analysis

This could lead to system instability or crashes if panic_on_warn is enabled. It may also cause network connectivity issues with Thunderbolt devices and improper resource management, potentially affecting other network connections.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the net: thunderbolt connection failure issue. Monitor kernel logs for thunderbolt-related errors indicating connection failures.

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