---
id: "CVE-2026-98754"
kind: "vulnerability"
aliases: ["CVE-2026-98754"]
title: "Linux kernel: race in vcc driver can cause use-after-free on tty cleanup"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["ldom", "linux-kernel", "other", "sparc", "virtualized-guests"]
not_affected_if: ["vcc-driver-not-loaded"]
published_at: "2026-10-18T16:17:29+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:16:54+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98754", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel: race in vcc driver can cause use-after-free on tty cleanup

The Linux kernel's vcc (Sun LDOM virtual console) driver clears a tty pointer without holding the port lock, so an LDC event callback can run concurrently and dereference a tty that was already freed. The sources describe this as a use-after-free, which can crash the kernel or be abused for code execution, but they do not state a severity or exploitability.

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

## How to check

- Check the running kernel version with `uname -r` and compare it against the fixed kernel versions listed in the NVD entry (unknown from the sources)
- Check whether the vcc driver is in use: `lsmod | grep vcc` or `grep -r vcc /proc/devices` (unknown from the sources)

## Fix

- Update the Linux kernel to a release that includes the upstream commit 'tty: vcc: hold port lock when clearing tty pointer in vcc_cleanup' (exact version unknown from the sources)

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98754

## From the sources

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

tty: vcc: hold port lock when clearing tty pointer in vcc_cleanup

vcc_cleanup() sets port->tty to NULL without holding port->lock, racing
with vcc_event() LDC callbacks that read port->tty under port->lock and
then use tty->port. This can cause a use-after-free when the callback
dereferences tty->port after cleanup has already destroyed and freed it.

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