---
id: "CVE-2026-98967"
kind: "vulnerability"
aliases: ["CVE-2026-98967"]
title: "Linux kernel cxgb4 TLS offload can deadlock on XArray lock"
severity: "unknown"
cvss: null
epss: 0.00209
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["chelsio-cxgb4", "infrastructure", "ktls", "linux-kernel"]
not_affected_if: ["ktls-offload-unused", "no-chelsio-hardware"]
published_at: "2026-10-23T13:17:18+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98967", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-98967", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux kernel cxgb4 TLS offload can deadlock on XArray lock

In the Linux kernel's cxgb4 Chelsio driver for kTLS offload, cleanup paths erase entries from a shared XArray without disabling softirqs, so a receive softirq on the same CPU can spin on a lock held by the interrupted task. The sources describe a lock-ordering hang, not code execution or data theft.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- Install a Linux kernel build that includes the upstream commit replacing xa_erase() with xa_erase_bh() in cxgb4/ch_ktls (unknown fixed version in sources)

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98967
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-98967

## From the sources

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

cxgb4/ch_ktls: disable softirqs around tid_list erases

chcr_ktls_cpl_act_open_rpl() inserts into tid_list from the receive path
using xa_insert_bh().  The array is shared by the adapter's connections
and initialized with XA_FLAGS_LOCK_BH.  However, chcr_ktls_dev_del() and
the chcr_ktls_dev_add() error path use xa_erase(), which takes the XArray
lock without disabling softirqs.

When cleanup runs with softirqs enabled, a receive softirq for another
connection on the same CPU can interrupt the erase and spin on the lock
held by the interrupted task.  Use xa_erase_bh() at both sites to match
the insertion path.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_